1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Concepts</title> 5<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../index.html" title="Chapter 1. Boost.Histogram"> 8<link rel="up" href="../index.html" title="Chapter 1. Boost.Histogram"> 9<link rel="prev" href="benchmarks.html" title="Benchmarks"> 10<link rel="next" href="reference.html" title="Reference"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="benchmarks.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="reference.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 27<a name="histogram.concepts"></a><a class="link" href="concepts.html" title="Concepts">Concepts</a> 28</h2></div></div></div> 29<div class="toc"><dl class="toc"> 30<dt><span class="section"><a href="concepts.html#histogram.concepts.Axis">Axis</a></span></dt> 31<dt><span class="section"><a href="concepts.html#histogram.concepts.DiscreteAxis">DiscreteAxis</a></span></dt> 32<dt><span class="section"><a href="concepts.html#histogram.concepts.IntervalAxis">IntervalAxis</a></span></dt> 33<dt><span class="section"><a href="concepts.html#histogram.concepts.Transform">Transform</a></span></dt> 34<dt><span class="section"><a href="concepts.html#histogram.concepts.Storage">Storage</a></span></dt> 35<dt><span class="section"><a href="concepts.html#histogram.concepts.Accumulator">Accumulator</a></span></dt> 36</dl></div> 37<p> 38 Users can extend the library with various new types whose concepts are defined 39 here. 40 </p> 41<div class="section"> 42<div class="titlepage"><div><div><h3 class="title"> 43<a name="histogram.concepts.Axis"></a><a class="link" href="concepts.html#histogram.concepts.Axis" title="Axis">Axis</a> 44</h3></div></div></div> 45<p> 46 An <span class="bold"><strong>Axis</strong></span> maps input values to indices. It 47 holds state specific to that axis, like the number of bins and any metadata. 48 Must be <a href="https://en.cppreference.com/w/cpp/named_req/CopyConstructible" target="_top">CopyConstructible</a>, 49 <a href="https://en.cppreference.com/w/cpp/named_req/CopyAssignable" target="_top">CopyAssignable</a>, 50 and <span class="bold"><strong>nothrow</strong></span> <a href="https://en.cppreference.com/w/cpp/named_req/MoveAssignable" target="_top">MoveAssignable</a>. 51 </p> 52<h5> 53<a name="histogram.concepts.Axis.h0"></a> 54 <span class="phrase"><a name="histogram.concepts.Axis.associated_types"></a></span><a class="link" href="concepts.html#histogram.concepts.Axis.associated_types">Associated 55 Types</a> 56 </h5> 57<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 58<li class="listitem"> 59 <a class="link" href="concepts.html#histogram.concepts.DiscreteAxis" title="DiscreteAxis"><span class="bold"><strong>DiscreteAxis</strong></span></a> 60 </li> 61<li class="listitem"> 62 <a class="link" href="concepts.html#histogram.concepts.IntervalAxis" title="IntervalAxis"><span class="bold"><strong>IntervalAxis</strong></span></a> 63 </li> 64</ul></div> 65<h5> 66<a name="histogram.concepts.Axis.h1"></a> 67 <span class="phrase"><a name="histogram.concepts.Axis.required_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Axis.required_features">Required 68 features</a> 69 </h5> 70<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 71<li class="listitem"> 72 <code class="computeroutput"><span class="identifier">A</span></code> is a type meeting the 73 requirements of <span class="bold"><strong>Axis</strong></span> 74 </li> 75<li class="listitem"> 76 <code class="computeroutput"><span class="identifier">a</span></code> is a value of type 77 <code class="computeroutput"><span class="identifier">A</span></code> 78 </li> 79<li class="listitem"> 80 <code class="computeroutput"><span class="identifier">I</span></code> is an alias for <code class="computeroutput"><a class="link" href="reference.html#header.boost.histogram.fwd_hpp" title="Header <boost/histogram/fwd.hpp>">boost::histogram::axis::index_type</a></code> 81 </li> 82</ul></div> 83<div class="table"> 84<a name="histogram.concepts.Axis.valid_expressions"></a><p class="title"><b>Table 1.1. Valid expressions</b></p> 85<div class="table-contents"><table class="table" summary="Valid expressions"> 86<colgroup> 87<col> 88<col> 89<col> 90</colgroup> 91<thead><tr> 92<th> 93 <p> 94 Expression 95 </p> 96 </th> 97<th> 98 <p> 99 Returns 100 </p> 101 </th> 102<th> 103 <p> 104 Semantics, Pre/Post-conditions 105 </p> 106 </th> 107</tr></thead> 108<tbody> 109<tr> 110<td> 111 <p> 112 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code> 113 </p> 114 </td> 115<td> 116 <p> 117 <code class="computeroutput"><span class="identifier">I</span></code> 118 </p> 119 </td> 120<td> 121 <p> 122 Const member function which returns the number of bins of the axis. 123 All indices from <code class="computeroutput"><span class="number">0</span></code> 124 to <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> 125 <span class="special">-</span> <span class="number">1</span></code> 126 must be valid and address a bin of the axis. 127 </p> 128 </td> 129</tr> 130<tr> 131<td> 132 <p> 133 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">index</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span></code> 134 </p> 135 </td> 136<td> 137 <p> 138 <code class="computeroutput"><span class="identifier">I</span></code> 139 </p> 140 </td> 141<td> 142 <p> 143 Const member function which maps a value <code class="computeroutput"><span class="identifier">v</span></code> 144 to an index. The mapping must be injective: each value must be 145 uniquely mapped to one index. If the value is not covered by the 146 axis, return either <code class="computeroutput"><span class="special">-</span><span class="number">1</span></code> or <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>. The value <code class="computeroutput"><span class="special">-</span><span class="number">1</span></code> indicates that the value is lower 147 than the lowest value covered by the axis. The value <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code> 148 indicates that the value is above the uppermost value covered by 149 the axis. By convention, <span class="emphasis"><em>NaN</em></span>-values are mapped 150 to <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>. 151 </p> 152 </td> 153</tr> 154<tr> 155<td> 156 <p> 157 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">get_allocator</span><span class="special">()</span></code> 158 </p> 159 </td> 160<td> 161 <p> 162 <code class="computeroutput"><span class="identifier">Alloc</span></code> 163 </p> 164 </td> 165<td> 166 <p> 167 Const member function which returns the allocator <code class="computeroutput"><span class="identifier">Alloc</span></code> used by this axis. May 168 be omitted if <code class="computeroutput"><span class="identifier">A</span></code> 169 does not use allocators. If this member function exists, also a 170 special constructor must exists so that <code class="computeroutput"><span class="identifier">A</span><span class="special">(</span><span class="identifier">a</span><span class="special">.</span><span class="identifier">get_allocator</span><span class="special">())</span></code> is a valid expression. 171 </p> 172 </td> 173</tr> 174</tbody> 175</table></div> 176</div> 177<br class="table-break"><h5> 178<a name="histogram.concepts.Axis.h2"></a> 179 <span class="phrase"><a name="histogram.concepts.Axis.optional_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Axis.optional_features">Optional 180 features</a> 181 </h5> 182<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 183<li class="listitem"> 184 <code class="computeroutput"><span class="identifier">A</span></code> is a type meeting the 185 requirements of <span class="bold"><strong>Axis</strong></span> 186 </li> 187<li class="listitem"> 188 <code class="computeroutput"><span class="identifier">a</span></code> and <code class="computeroutput"><span class="identifier">b</span></code> 189 are values of type <code class="computeroutput"><span class="identifier">A</span></code> 190 </li> 191<li class="listitem"> 192 <code class="computeroutput"><span class="identifier">i</span></code> and <code class="computeroutput"><span class="identifier">j</span></code> 193 are indices of type <code class="computeroutput"><a class="link" href="reference.html#header.boost.histogram.fwd_hpp" title="Header <boost/histogram/fwd.hpp>">boost::histogram::axis::index_type</a></code> 194 </li> 195<li class="listitem"> 196 <code class="computeroutput"><span class="identifier">n</span></code> is a value of type 197 <code class="computeroutput"><span class="keyword">unsigned</span></code> 198 </li> 199<li class="listitem"> 200 <code class="computeroutput"><span class="identifier">M</span></code> is a metadata type 201 that is <a href="https://en.cppreference.com/w/cpp/named_req/CopyConstructible" target="_top">CopyConstructible</a> 202 and <a href="https://en.cppreference.com/w/cpp/named_req/CopyAssignable" target="_top">CopyAssignable</a> 203 and <span class="bold"><strong>nothrow</strong></span> <a href="https://en.cppreference.com/w/cpp/named_req/MoveAssignable" target="_top">MoveAssignable</a>. 204 </li> 205<li class="listitem"> 206 <code class="computeroutput"><span class="identifier">ar</span></code> is a value of an archive 207 with Boost.Serialization semantics 208 </li> 209</ul></div> 210<div class="table"> 211<a name="histogram.concepts.Axis.valid_expressions0"></a><p class="title"><b>Table 1.2. Valid expressions</b></p> 212<div class="table-contents"><table class="table" summary="Valid expressions"> 213<colgroup> 214<col> 215<col> 216<col> 217</colgroup> 218<thead><tr> 219<th> 220 <p> 221 Expression 222 </p> 223 </th> 224<th> 225 <p> 226 Returns 227 </p> 228 </th> 229<th> 230 <p> 231 Semantics, Pre/Post-conditions 232 </p> 233 </th> 234</tr></thead> 235<tbody> 236<tr> 237<td> 238 <p> 239 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">update</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span></code> 240 </p> 241 </td> 242<td> 243 <p> 244 <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">I</span><span class="special">,</span> 245 <span class="identifier">I</span><span class="special">></span></code> 246 </p> 247 </td> 248<td> 249 <p> 250 Non-const member function which maps a value to an index (first 251 argument of the returned pair) and offset (second argument of the 252 returned pair). If the value is not covered by the axis, this method 253 may grow the current axis size (<code class="computeroutput"><span class="identifier">old_size</span></code>) 254 by the number of bins needed to contain the value or more (<code class="computeroutput"><span class="identifier">new_size</span></code>). If the value is below 255 the lowest value covered by the axis, return index <code class="computeroutput"><span class="number">0</span></code> and offset <code class="computeroutput"><span class="identifier">new_size</span> 256 <span class="special">-</span> <span class="identifier">old_size</span></code>. 257 If the value is above the uppermost value covered by the axis, 258 return index <code class="computeroutput"><span class="identifier">new_size</span> 259 <span class="special">-</span> <span class="number">1</span></code> 260 and a negative offset <code class="computeroutput"><span class="identifier">old_size</span> 261 <span class="special">-</span> <span class="identifier">new_size</span></code>. 262 If the value is outside, but the axis is not enlarged, then return 263 an index equivalent to <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">index</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span></code> and offset <code class="computeroutput"><span class="number">0</span></code>. 264 </p> 265 </td> 266</tr> 267<tr> 268<td> 269 <p> 270 <code class="computeroutput"><span class="identifier">A</span><span class="special">(</span><span class="identifier">a</span><span class="special">,</span> 271 <span class="identifier">i</span><span class="special">,</span> 272 <span class="identifier">j</span><span class="special">,</span> 273 <span class="identifier">n</span><span class="special">)</span></code> 274 </p> 275 </td> 276<td> 277 </td> 278<td> 279 <p> 280 Special constructor used by the reduce algorithm. <code class="computeroutput"><span class="identifier">a</span></code> is the original axis instance, 281 <code class="computeroutput"><span class="identifier">i</span></code> and <code class="computeroutput"><span class="identifier">j</span></code> are the index range to keep 282 in the reduced axis. If <code class="computeroutput"><span class="identifier">n</span></code> 283 is larger than 1, <code class="computeroutput"><span class="identifier">n</span></code> 284 adjacent bins are merged into one larger cell. If this constructor 285 is not implemented, <code class="computeroutput"><a class="link" href="../boost/histogram/algorithm/reduce_idm45503931121408.html" title="Function template reduce">boost::histogram::algorithm::reduce</a></code> 286 throws an exception on an attempt to reduce this axis. 287 </p> 288 </td> 289</tr> 290<tr> 291<td> 292 <p> 293 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">options</span><span class="special">()</span></code> 294 </p> 295 </td> 296<td> 297 <p> 298 <code class="computeroutput"><span class="keyword">unsigned</span></code> 299 </p> 300 </td> 301<td> 302 <p> 303 Static constexpr member function which returns the <code class="computeroutput"><a class="link" href="reference.html#header.boost.histogram.axis.option_hpp" title="Header <boost/histogram/axis/option.hpp>">axis options</a></code> 304 for this axis. 305 </p> 306 </td> 307</tr> 308<tr> 309<td> 310 <p> 311 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">inclusive</span><span class="special">()</span></code> 312 </p> 313 </td> 314<td> 315 <p> 316 <code class="computeroutput"><span class="keyword">bool</span></code> 317 </p> 318 </td> 319<td> 320 <p> 321 Static constexpr member function which returns true, if the axis 322 has a bin for every possible input value, and false otherwise. 323 Faster code can be generated if all axes types in a histogram are 324 inclusive. An axis with underflow and overflow bins is always inclusive. 325 An axis may be inclusive even if underflow or overflow bins are 326 missing. For example, a category axis is inclusive if either it 327 has an overflow bin or if it is growing. 328 </p> 329 </td> 330</tr> 331<tr> 332<td> 333 <p> 334 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">metadata</span><span class="special">()</span></code> 335 </p> 336 </td> 337<td> 338 <p> 339 <code class="computeroutput"><span class="identifier">M</span><span class="special">&</span></code> 340 </p> 341 </td> 342<td> 343 <p> 344 Const and non-const member functions must exist, which both returns 345 a mutable reference to the metadata associated with the axis (usually 346 a string). 347 </p> 348 </td> 349</tr> 350<tr> 351<td> 352 <p> 353 <code class="computeroutput"><span class="identifier">a</span> <span class="special">==</span> 354 <span class="identifier">b</span></code> 355 </p> 356 </td> 357<td> 358 <p> 359 <code class="computeroutput"><span class="keyword">bool</span></code> 360 </p> 361 </td> 362<td> 363 <p> 364 Returns <code class="computeroutput"><span class="keyword">true</span></code> if all 365 state variables compare equal, including any metadata. Otherwise 366 returns <code class="computeroutput"><span class="keyword">false</span></code>. If 367 <code class="computeroutput"><span class="identifier">a</span> <span class="special">==</span> 368 <span class="identifier">b</span></code> is implemented, also 369 <code class="computeroutput"><span class="identifier">a</span> <span class="special">!=</span> 370 <span class="identifier">b</span></code> must be implemented. 371 If this binary operator is not implemented, the library considers 372 the axes equal if their types are the same. 373 </p> 374 </td> 375</tr> 376<tr> 377<td> 378 <p> 379 <code class="computeroutput"><span class="identifier">a</span> <span class="special">!=</span> 380 <span class="identifier">b</span></code> 381 </p> 382 </td> 383<td> 384 <p> 385 <code class="computeroutput"><span class="keyword">bool</span></code> 386 </p> 387 </td> 388<td> 389 <p> 390 Must be implemented if <code class="computeroutput"><span class="identifier">a</span> 391 <span class="special">==</span> <span class="identifier">b</span></code> 392 is implemented and must be equal to <code class="computeroutput"><span class="special">!(</span><span class="identifier">a</span> <span class="special">==</span> 393 <span class="identifier">b</span><span class="special">)</span></code>. 394 </p> 395 </td> 396</tr> 397<tr> 398<td> 399 <p> 400 <code class="computeroutput"><span class="identifier">os</span> <span class="special"><<</span> 401 <span class="identifier">a</span></code> 402 </p> 403 </td> 404<td> 405 <p> 406 <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> 407 <span class="identifier">Traits</span><span class="special">>&</span></code> 408 </p> 409 </td> 410<td> 411 <p> 412 <code class="computeroutput"><span class="identifier">os</span></code> is a value of 413 type <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> 414 <span class="identifier">Traits</span><span class="special">></span></code>. 415 Streams a text representation of the axis. May not mutate <code class="computeroutput"><span class="identifier">a</span></code>. 416 </p> 417 </td> 418</tr> 419<tr> 420<td> 421 <p> 422 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">serialize</span><span class="special">(</span><span class="identifier">ar</span><span class="special">,</span> 423 <span class="identifier">n</span><span class="special">)</span></code> 424 </p> 425 </td> 426<td> 427 </td> 428<td> 429 <p> 430 Saves to the archive or loads serialised state from the archive. 431 The version number <code class="computeroutput"><span class="identifier">n</span></code> 432 is the stored version when the object is loaded or the current 433 version when the object is saved. 434 </p> 435 </td> 436</tr> 437</tbody> 438</table></div> 439</div> 440<br class="table-break"><h5> 441<a name="histogram.concepts.Axis.h3"></a> 442 <span class="phrase"><a name="histogram.concepts.Axis.models"></a></span><a class="link" href="concepts.html#histogram.concepts.Axis.models">Models</a> 443 </h5> 444<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 445<li class="listitem"> 446 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/boolean.html" title="Class template boolean">boost::histogram::axis::boolean</a></code> 447 </li> 448<li class="listitem"> 449 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/category.html" title="Class template category">boost::histogram::axis::category</a></code> 450 </li> 451<li class="listitem"> 452 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/integer.html" title="Class template integer">boost::histogram::axis::integer</a></code> 453 </li> 454<li class="listitem"> 455 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/regular.html" title="Class template regular">boost::histogram::axis::regular</a></code> 456 </li> 457<li class="listitem"> 458 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/variable.html" title="Class template variable">boost::histogram::axis::variable</a></code> 459 </li> 460</ul></div> 461</div> 462<div class="section"> 463<div class="titlepage"><div><div><h3 class="title"> 464<a name="histogram.concepts.DiscreteAxis"></a><a class="link" href="concepts.html#histogram.concepts.DiscreteAxis" title="DiscreteAxis">DiscreteAxis</a> 465</h3></div></div></div> 466<p> 467 A <span class="bold"><strong>DiscreteAxis</strong></span> is one of two optional refinements 468 of the <a class="link" href="concepts.html#histogram.concepts.Axis" title="Axis"><span class="bold"><strong>Axis</strong></span></a> 469 concept, the other one is the <a class="link" href="concepts.html#histogram.concepts.IntervalAxis" title="IntervalAxis">IntervalAxis</a>. 470 This concept is for axes in which each bin represents a single value instead 471 of an interval. 472 </p> 473<p> 474 Discrete axes can be further divided into ordered and unordered. An axis 475 is ordered, when bin indices i < j < k imply that value[i] < value[j] 476 < value[k] or value[i] > value[j] > value[k] for all i, j, k. The 477 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/integer.html" title="Class template integer">integer axis</a></code> 478 is ordered and the <code class="computeroutput"><a class="link" href="../boost/histogram/axis/category.html" title="Class template category">category 479 axis</a></code> is unordered. 480 </p> 481<p> 482 An unordered discrete axis cannot have an underflow bin. Since there is no 483 order, one can have at most one extra bin that counts values not handled 484 by the axis. By convention the overflow bin is used for that. 485 </p> 486<h5> 487<a name="histogram.concepts.DiscreteAxis.h0"></a> 488 <span class="phrase"><a name="histogram.concepts.DiscreteAxis.associated_types"></a></span><a class="link" href="concepts.html#histogram.concepts.DiscreteAxis.associated_types">Associated 489 Types</a> 490 </h5> 491<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 492<li class="listitem"> 493 <a class="link" href="concepts.html#histogram.concepts.Axis" title="Axis"><span class="bold"><strong>Axis</strong></span></a> 494 </li> 495<li class="listitem"> 496 <a class="link" href="concepts.html#histogram.concepts.IntervalAxis" title="IntervalAxis"><span class="bold"><strong>IntervalAxis</strong></span></a> 497 </li> 498</ul></div> 499<h5> 500<a name="histogram.concepts.DiscreteAxis.h1"></a> 501 <span class="phrase"><a name="histogram.concepts.DiscreteAxis.optional_features"></a></span><a class="link" href="concepts.html#histogram.concepts.DiscreteAxis.optional_features">Optional 502 features</a> 503 </h5> 504<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 505<li class="listitem"> 506 <code class="computeroutput"><span class="identifier">A</span></code> is a type meeting the 507 requirements of <span class="bold"><strong>DiscreteAxis</strong></span> 508 </li> 509<li class="listitem"> 510 <code class="computeroutput"><span class="identifier">a</span></code> is a value of type 511 <code class="computeroutput"><span class="identifier">A</span></code> 512 </li> 513<li class="listitem"> 514 <code class="computeroutput"><span class="identifier">V</span></code> is the type accepted 515 for conversion into an index 516 </li> 517<li class="listitem"> 518 <code class="computeroutput"><span class="identifier">v</span></code> is a value of type 519 <code class="computeroutput"><span class="identifier">V</span></code> 520 </li> 521<li class="listitem"> 522 <code class="computeroutput"><span class="identifier">i</span></code> is a value of type 523 <code class="computeroutput"><a class="link" href="reference.html#header.boost.histogram.fwd_hpp" title="Header <boost/histogram/fwd.hpp>">boost::histogram::axis::index_type</a></code> 524 </li> 525<li class="listitem"> 526 <code class="computeroutput"><span class="identifier">AxisIter</span></code> is an <span class="emphasis"><em>RandomAccessIterator</em></span> 527 over the bins of <code class="computeroutput"><span class="identifier">A</span></code> 528 </li> 529<li class="listitem"> 530 <code class="computeroutput"><span class="identifier">ReAxisIter</span></code> is a reverse 531 <span class="emphasis"><em>RandomAccessIterator</em></span> over the bins of <code class="computeroutput"><span class="identifier">A</span></code> 532 </li> 533</ul></div> 534<div class="table"> 535<a name="histogram.concepts.DiscreteAxis.valid_expressions"></a><p class="title"><b>Table 1.3. Valid expressions</b></p> 536<div class="table-contents"><table class="table" summary="Valid expressions"> 537<colgroup> 538<col> 539<col> 540<col> 541</colgroup> 542<thead><tr> 543<th> 544 <p> 545 Expression 546 </p> 547 </th> 548<th> 549 <p> 550 Returns 551 </p> 552 </th> 553<th> 554 <p> 555 Semantics, Pre/Post-conditions 556 </p> 557 </th> 558</tr></thead> 559<tbody> 560<tr> 561<td> 562 <p> 563 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">ordered</span><span class="special">()</span></code> 564 </p> 565 </td> 566<td> 567 <p> 568 <code class="computeroutput"><span class="keyword">bool</span></code> 569 </p> 570 </td> 571<td> 572 <p> 573 Static constexpr member function which returns true if the axis 574 is ordered and false otherwise. If this is absent, the library 575 checks whether the value type is arithmetic instead, see <code class="computeroutput"><a class="link" href="../boost/histogram/axis/traits/ordered.html" title="Function template ordered">boost::histogram::axis::traits::ordered</a></code>. 576 </p> 577 </td> 578</tr> 579<tr> 580<td> 581 <p> 582 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span></code> 583 </p> 584 </td> 585<td> 586 <p> 587 <code class="computeroutput"><span class="identifier">V</span></code> 588 </p> 589 </td> 590<td> 591 <p> 592 Const member function which maps an index to a value. The mapping 593 must be injective: each index must be uniquely mapped to one value. 594 The effect must be exactly the inverse of <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">index</span><span class="special">(</span><span class="identifier">v</span><span class="special">)</span></code>. The return value may be a const 595 reference, if the lifetime of the referred object is equal to the 596 lifetime of the axis. 597 </p> 598 </td> 599</tr> 600<tr> 601<td> 602 <p> 603 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">bin</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span></code> 604 </p> 605 </td> 606<td> 607 <p> 608 <code class="computeroutput"><span class="identifier">V</span></code> 609 </p> 610 </td> 611<td> 612 <p> 613 Must have the same effect as <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span></code>. 614 </p> 615 </td> 616</tr> 617<tr> 618<td> 619 <p> 620 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">begin</span><span class="special">()</span></code> 621 </p> 622 </td> 623<td> 624 <p> 625 <code class="computeroutput"><span class="identifier">AxisIter</span></code> 626 </p> 627 </td> 628<td> 629 <p> 630 Const member function which return an iterator to the bin with 631 index <code class="computeroutput"><span class="number">0</span></code>. 632 </p> 633 </td> 634</tr> 635<tr> 636<td> 637 <p> 638 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">end</span><span class="special">()</span></code> 639 </p> 640 </td> 641<td> 642 <p> 643 <code class="computeroutput"><span class="identifier">AxisIter</span></code> 644 </p> 645 </td> 646<td> 647 <p> 648 Const member function which returns an iterator to the bin with 649 index <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>. 650 </p> 651 </td> 652</tr> 653<tr> 654<td> 655 <p> 656 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">rbegin</span><span class="special">()</span></code> 657 </p> 658 </td> 659<td> 660 <p> 661 <code class="computeroutput"><span class="identifier">ReAxisIter</span></code> 662 </p> 663 </td> 664<td> 665 <p> 666 Const member function which return a reverse iterator to the bin 667 with index <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">()-</span><span class="number">1</span></code>. 668 </p> 669 </td> 670</tr> 671<tr> 672<td> 673 <p> 674 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">rend</span><span class="special">()</span></code> 675 </p> 676 </td> 677<td> 678 <p> 679 <code class="computeroutput"><span class="identifier">ReAxisIter</span></code> 680 </p> 681 </td> 682<td> 683 <p> 684 Const member function which returns an iterator to the bin with 685 index <code class="computeroutput"><span class="special">-</span><span class="number">1</span></code>. 686 </p> 687 </td> 688</tr> 689</tbody> 690</table></div> 691</div> 692<br class="table-break"><div class="tip"><table border="0" summary="Tip"> 693<tr> 694<td rowspan="2" align="center" valign="top" width="25"><img alt="[Tip]" src="../../../../../doc/src/images/tip.png"></td> 695<th align="left">Tip</th> 696</tr> 697<tr><td align="left" valign="top"><p> 698 The complete iterator interface can be added to a user-defined axis which 699 implements <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">bin</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span></code> by 700 inheriting from the <code class="computeroutput"><a class="link" href="../boost/histogram/axis/iterator_mixin.html" title="Class template iterator_mixin">iterator_mixin</a></code>. 701 </p></td></tr> 702</table></div> 703<h5> 704<a name="histogram.concepts.DiscreteAxis.h2"></a> 705 <span class="phrase"><a name="histogram.concepts.DiscreteAxis.models"></a></span><a class="link" href="concepts.html#histogram.concepts.DiscreteAxis.models">Models</a> 706 </h5> 707<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 708<li class="listitem"> 709 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/category.html" title="Class template category">boost::histogram::axis::category</a></code> 710 </li> 711<li class="listitem"> 712 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/integer.html" title="Class template integer">boost::histogram::axis::integer</a></code>, 713 if first template parameter is <code class="computeroutput"><span class="keyword">int</span></code> 714 </li> 715</ul></div> 716</div> 717<div class="section"> 718<div class="titlepage"><div><div><h3 class="title"> 719<a name="histogram.concepts.IntervalAxis"></a><a class="link" href="concepts.html#histogram.concepts.IntervalAxis" title="IntervalAxis">IntervalAxis</a> 720</h3></div></div></div> 721<p> 722 A <span class="bold"><strong>IntervalAxis</strong></span> is one of two optional refinements 723 of the <a class="link" href="concepts.html#histogram.concepts.Axis" title="Axis"><span class="bold"><strong>Axis</strong></span></a> 724 concept, the other one is the <a class="link" href="concepts.html#histogram.concepts.DiscreteAxis" title="DiscreteAxis">DiscreteAxis</a>. 725 It is for ordered values that form intervals with a well-defined lower and 726 upper edge, and a center. Each bin represents an interval of values. 727 </p> 728<h5> 729<a name="histogram.concepts.IntervalAxis.h0"></a> 730 <span class="phrase"><a name="histogram.concepts.IntervalAxis.associated_types"></a></span><a class="link" href="concepts.html#histogram.concepts.IntervalAxis.associated_types">Associated 731 Types</a> 732 </h5> 733<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 734<li class="listitem"> 735 <a class="link" href="concepts.html#histogram.concepts.Axis" title="Axis"><span class="bold"><strong>Axis</strong></span></a> 736 </li> 737<li class="listitem"> 738 <a class="link" href="concepts.html#histogram.concepts.DiscreteAxis" title="DiscreteAxis"><span class="bold"><strong>DiscreteAxis</strong></span></a> 739 </li> 740</ul></div> 741<h5> 742<a name="histogram.concepts.IntervalAxis.h1"></a> 743 <span class="phrase"><a name="histogram.concepts.IntervalAxis.optional_features"></a></span><a class="link" href="concepts.html#histogram.concepts.IntervalAxis.optional_features">Optional 744 features</a> 745 </h5> 746<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 747<li class="listitem"> 748 <code class="computeroutput"><span class="identifier">A</span></code> is a type meeting the 749 requirements of <span class="bold"><strong>IntervalAxis</strong></span> 750 </li> 751<li class="listitem"> 752 <code class="computeroutput"><span class="identifier">a</span></code> is a value of type 753 <code class="computeroutput"><span class="identifier">A</span></code> 754 </li> 755<li class="listitem"> 756 <code class="computeroutput"><span class="identifier">V</span></code> is the type accepted 757 for conversion into an index 758 </li> 759<li class="listitem"> 760 <code class="computeroutput"><span class="identifier">B</span></code> is the type that represents 761 the bin interval 762 </li> 763<li class="listitem"> 764 <code class="computeroutput"><span class="identifier">v</span></code> is a value of type 765 <code class="computeroutput"><span class="identifier">V</span></code> 766 </li> 767<li class="listitem"> 768 <code class="computeroutput"><span class="identifier">i</span></code> is a value of type 769 <code class="computeroutput"><a class="link" href="reference.html#header.boost.histogram.fwd_hpp" title="Header <boost/histogram/fwd.hpp>">boost::histogram::axis::index_type</a></code> 770 </li> 771<li class="listitem"> 772 <code class="computeroutput"><span class="identifier">j</span></code> is a value of type 773 <code class="computeroutput"><a class="link" href="reference.html#header.boost.histogram.fwd_hpp" title="Header <boost/histogram/fwd.hpp>">boost::histogram::axis::real_index_type</a></code> 774 </li> 775<li class="listitem"> 776 <code class="computeroutput"><span class="identifier">AxisIter</span></code> is an <span class="emphasis"><em>RandomAccessIterator</em></span> 777 over the bins of <code class="computeroutput"><span class="identifier">A</span></code> 778 </li> 779<li class="listitem"> 780 <code class="computeroutput"><span class="identifier">ReAxisIter</span></code> is a reverse 781 <span class="emphasis"><em>RandomAccessIterator</em></span> over the bins of <code class="computeroutput"><span class="identifier">A</span></code> 782 </li> 783</ul></div> 784<div class="table"> 785<a name="histogram.concepts.IntervalAxis.valid_expressions"></a><p class="title"><b>Table 1.4. Valid expressions</b></p> 786<div class="table-contents"><table class="table" summary="Valid expressions"> 787<colgroup> 788<col> 789<col> 790<col> 791</colgroup> 792<thead><tr> 793<th> 794 <p> 795 Expression 796 </p> 797 </th> 798<th> 799 <p> 800 Returns 801 </p> 802 </th> 803<th> 804 <p> 805 Semantics, Pre/Post-conditions 806 </p> 807 </th> 808</tr></thead> 809<tbody> 810<tr> 811<td> 812 <p> 813 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span></code> 814 </p> 815 </td> 816<td> 817 <p> 818 <code class="computeroutput"><span class="identifier">V</span></code> 819 </p> 820 </td> 821<td> 822 <p> 823 Const member function which maps an index to a value. The mapping 824 must be injective: each index must be uniquely mapped to one value. 825 The result of <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="identifier">a</span><span class="special">.</span><span class="identifier">index</span><span class="special">(</span><span class="identifier">v</span><span class="special">))</span></code> should agree to very high precision 826 with <code class="computeroutput"><span class="identifier">v</span></code> (the mapping 827 may not be exact due to the finite precision of floating point 828 computations). The return value may be a const reference, if the 829 lifetime of the referred object is equal to the lifetime of the 830 axis. <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="identifier">j</span><span class="special">)</span></code> 831 is expected to return the lower edge of the bin, <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="identifier">j</span><span class="special">+</span><span class="number">1</span><span class="special">)</span></code> 832 the upper edge, and <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="identifier">j</span> 833 <span class="special">+</span> <span class="number">0.5</span><span class="special">)</span></code> the center. 834 </p> 835 </td> 836</tr> 837<tr> 838<td> 839 <p> 840 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">bin</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span></code> 841 </p> 842 </td> 843<td> 844 <p> 845 <code class="computeroutput"><span class="identifier">B</span></code> 846 </p> 847 </td> 848<td> 849 <p> 850 Const member function which returns an instance that represents 851 the current bin. Nothing about the type is required, but it is 852 recommended that the type has the methods <code class="computeroutput"><span class="identifier">B</span><span class="special">::</span><span class="identifier">lower</span><span class="special">()</span></code>, <code class="computeroutput"><span class="identifier">B</span><span class="special">::</span><span class="identifier">upper</span><span class="special">()</span></code>, and <code class="computeroutput"><span class="identifier">B</span><span class="special">::</span><span class="identifier">center</span><span class="special">()</span></code> similar to the types used by 853 the builtin axis models. The return value may be a const reference, 854 if the lifetime of the referred object is equal to the lifetime 855 of the axis. 856 </p> 857 </td> 858</tr> 859<tr> 860<td> 861 <p> 862 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">begin</span><span class="special">()</span></code> 863 </p> 864 </td> 865<td> 866 <p> 867 <code class="computeroutput"><span class="identifier">AxisIter</span></code> 868 </p> 869 </td> 870<td> 871 <p> 872 Const member function which return an iterator to the bin with 873 index <code class="computeroutput"><span class="number">0</span></code>. 874 </p> 875 </td> 876</tr> 877<tr> 878<td> 879 <p> 880 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">end</span><span class="special">()</span></code> 881 </p> 882 </td> 883<td> 884 <p> 885 <code class="computeroutput"><span class="identifier">AxisIter</span></code> 886 </p> 887 </td> 888<td> 889 <p> 890 Const member function which returns an iterator to the bin with 891 index <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>. 892 </p> 893 </td> 894</tr> 895<tr> 896<td> 897 <p> 898 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">rbegin</span><span class="special">()</span></code> 899 </p> 900 </td> 901<td> 902 <p> 903 <code class="computeroutput"><span class="identifier">ReAxisIter</span></code> 904 </p> 905 </td> 906<td> 907 <p> 908 Const member function which return a reverse iterator to the bin 909 with index <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">()-</span><span class="number">1</span></code>. 910 </p> 911 </td> 912</tr> 913<tr> 914<td> 915 <p> 916 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">rend</span><span class="special">()</span></code> 917 </p> 918 </td> 919<td> 920 <p> 921 <code class="computeroutput"><span class="identifier">ReAxisIter</span></code> 922 </p> 923 </td> 924<td> 925 <p> 926 Const member function which returns an iterator to the bin with 927 index <code class="computeroutput"><span class="special">-</span><span class="number">1</span></code>. 928 </p> 929 </td> 930</tr> 931</tbody> 932</table></div> 933</div> 934<br class="table-break"><div class="tip"><table border="0" summary="Tip"> 935<tr> 936<td rowspan="2" align="center" valign="top" width="25"><img alt="[Tip]" src="../../../../../doc/src/images/tip.png"></td> 937<th align="left">Tip</th> 938</tr> 939<tr><td align="left" valign="top"><p> 940 The complete iterator interface can be added to a user-defined axis which 941 implements <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">bin</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span></code> by 942 inheriting from the <code class="computeroutput"><a class="link" href="../boost/histogram/axis/iterator_mixin.html" title="Class template iterator_mixin">iterator_mixin</a></code>. 943 </p></td></tr> 944</table></div> 945<h5> 946<a name="histogram.concepts.IntervalAxis.h2"></a> 947 <span class="phrase"><a name="histogram.concepts.IntervalAxis.models"></a></span><a class="link" href="concepts.html#histogram.concepts.IntervalAxis.models">Models</a> 948 </h5> 949<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 950<li class="listitem"> 951 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/regular.html" title="Class template regular">boost::histogram::axis::regular</a></code> 952 </li> 953<li class="listitem"> 954 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/variable.html" title="Class template variable">boost::histogram::axis::variable</a></code> 955 </li> 956<li class="listitem"> 957 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/integer.html" title="Class template integer">boost::histogram::axis::integer</a></code>, 958 if first template parameter is a floating point type 959 </li> 960</ul></div> 961</div> 962<div class="section"> 963<div class="titlepage"><div><div><h3 class="title"> 964<a name="histogram.concepts.Transform"></a><a class="link" href="concepts.html#histogram.concepts.Transform" title="Transform">Transform</a> 965</h3></div></div></div> 966<p> 967 A <span class="bold"><strong>Transform</strong></span> implements a monotonic mapping 968 between two real-valued domains, external and internal. It is used to extend 969 the <code class="computeroutput"><a class="link" href="../boost/histogram/axis/regular.html" title="Class template regular">regular axis</a></code>. 970 The bins in the internal domain are of equal width, while the bins in the 971 external domain are non-equal width. Must be <a href="https://en.cppreference.com/w/cpp/named_req/DefaultConstructible" target="_top">DefaultConstructible</a>, 972 <a href="https://en.cppreference.com/w/cpp/named_req/CopyConstructible" target="_top">CopyConstructible</a>, 973 and <a href="https://en.cppreference.com/w/cpp/named_req/CopyAssignable" target="_top">CopyAssignable</a>. 974 </p> 975<h5> 976<a name="histogram.concepts.Transform.h0"></a> 977 <span class="phrase"><a name="histogram.concepts.Transform.required_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Transform.required_features">Required 978 features</a> 979 </h5> 980<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 981<li class="listitem"> 982 <code class="computeroutput"><span class="identifier">T</span></code> is a type meeting the 983 requirements of <span class="bold"><strong>Transform</strong></span> 984 </li> 985<li class="listitem"> 986 <code class="computeroutput"><span class="identifier">t</span></code> is a value of type 987 <code class="computeroutput"><span class="identifier">T</span></code> 988 </li> 989<li class="listitem"> 990 <code class="computeroutput"><span class="identifier">X</span></code> is a type with the 991 semantics of a floating-point type 992 </li> 993<li class="listitem"> 994 <code class="computeroutput"><span class="identifier">x</span></code> is a value of type 995 <code class="computeroutput"><span class="identifier">X</span></code> 996 </li> 997<li class="listitem"> 998 <code class="computeroutput"><span class="identifier">Y</span></code> is a floating-point 999 type 1000 </li> 1001<li class="listitem"> 1002 <code class="computeroutput"><span class="identifier">y</span></code> is a value of type 1003 <code class="computeroutput"><span class="identifier">Y</span></code> 1004 </li> 1005</ul></div> 1006<div class="table"> 1007<a name="histogram.concepts.Transform.valid_expressions"></a><p class="title"><b>Table 1.5. Valid expressions</b></p> 1008<div class="table-contents"><table class="table" summary="Valid expressions"> 1009<colgroup> 1010<col> 1011<col> 1012<col> 1013</colgroup> 1014<thead><tr> 1015<th> 1016 <p> 1017 Expression 1018 </p> 1019 </th> 1020<th> 1021 <p> 1022 Returns 1023 </p> 1024 </th> 1025<th> 1026 <p> 1027 Semantics, Pre/Post-conditions 1028 </p> 1029 </th> 1030</tr></thead> 1031<tbody> 1032<tr> 1033<td> 1034 <p> 1035 <code class="computeroutput"><span class="identifier">t</span><span class="special">.</span><span class="identifier">forward</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span></code> 1036 </p> 1037 </td> 1038<td> 1039 <p> 1040 <code class="computeroutput"><span class="identifier">Y</span></code> 1041 </p> 1042 </td> 1043<td> 1044 <p> 1045 Const or static member function which maps the external value to 1046 the corresponding internal value. The return type <code class="computeroutput"><span class="identifier">Y</span></code> may differ from <code class="computeroutput"><span class="identifier">X</span></code>. 1047 </p> 1048 </td> 1049</tr> 1050<tr> 1051<td> 1052 <p> 1053 <code class="computeroutput"><span class="identifier">t</span><span class="special">.</span><span class="identifier">inverse</span><span class="special">(</span><span class="identifier">y</span><span class="special">)</span></code> 1054 </p> 1055 </td> 1056<td> 1057 <p> 1058 <code class="computeroutput"><span class="identifier">X</span></code> 1059 </p> 1060 </td> 1061<td> 1062 <p> 1063 Const or static member function which maps the internal value to 1064 the corresponding external value. The result of <code class="computeroutput"><span class="identifier">t</span><span class="special">.</span><span class="identifier">inverse</span><span class="special">(</span><span class="identifier">t</span><span class="special">.</span><span class="identifier">forward</span><span class="special">(</span><span class="identifier">x</span><span class="special">))</span></code> must be approximately equal to 1065 <code class="computeroutput"><span class="identifier">x</span></code> within floating-point 1066 precision. 1067 </p> 1068 </td> 1069</tr> 1070<tr> 1071<td> 1072 <p> 1073 <code class="computeroutput"><span class="identifier">t</span> <span class="special">==</span> 1074 <span class="identifier">u</span></code> 1075 </p> 1076 </td> 1077<td> 1078 <p> 1079 <code class="computeroutput"><span class="keyword">bool</span></code> 1080 </p> 1081 </td> 1082<td> 1083 <p> 1084 <code class="computeroutput"><span class="identifier">u</span></code> is another value 1085 of type <code class="computeroutput"><span class="identifier">T</span></code>. Returns 1086 <code class="computeroutput"><span class="keyword">true</span></code> if both values 1087 have the same state. Otherwise returns <code class="computeroutput"><span class="keyword">false</span></code>. 1088 May be omitted if <code class="computeroutput"><span class="identifier">T</span></code> 1089 is stateless. If this binary operator is not implemented, the library 1090 considers the arguments equal, if and only if their types are the 1091 same. 1092 </p> 1093 </td> 1094</tr> 1095</tbody> 1096</table></div> 1097</div> 1098<br class="table-break"><h5> 1099<a name="histogram.concepts.Transform.h1"></a> 1100 <span class="phrase"><a name="histogram.concepts.Transform.optional_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Transform.optional_features">Optional 1101 features</a> 1102 </h5> 1103<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1104<li class="listitem"> 1105 <code class="computeroutput"><span class="identifier">T</span></code> is a type meeting the 1106 requirements of <span class="bold"><strong>Transform</strong></span> 1107 </li> 1108<li class="listitem"> 1109 <code class="computeroutput"><span class="identifier">t</span></code> is a value of type 1110 <code class="computeroutput"><span class="identifier">T</span></code> 1111 </li> 1112<li class="listitem"> 1113 <code class="computeroutput"><span class="identifier">ar</span></code> is a value of an archive 1114 with Boost.Serialization semantics 1115 </li> 1116</ul></div> 1117<div class="table"> 1118<a name="histogram.concepts.Transform.valid_expressions0"></a><p class="title"><b>Table 1.6. Valid expressions</b></p> 1119<div class="table-contents"><table class="table" summary="Valid expressions"> 1120<colgroup> 1121<col> 1122<col> 1123<col> 1124</colgroup> 1125<thead><tr> 1126<th> 1127 <p> 1128 Expression 1129 </p> 1130 </th> 1131<th> 1132 <p> 1133 Returns 1134 </p> 1135 </th> 1136<th> 1137 <p> 1138 Semantics, Pre/Post-conditions 1139 </p> 1140 </th> 1141</tr></thead> 1142<tbody><tr> 1143<td> 1144 <p> 1145 <code class="computeroutput"><span class="identifier">t</span><span class="special">.</span><span class="identifier">serialize</span><span class="special">(</span><span class="identifier">ar</span><span class="special">,</span> 1146 <span class="identifier">n</span><span class="special">)</span></code> 1147 </p> 1148 </td> 1149<td> 1150 </td> 1151<td> 1152 <p> 1153 <code class="computeroutput"><span class="identifier">ar</span></code> is a value of 1154 an archive with Boost.Serialization semantics and <code class="computeroutput"><span class="identifier">n</span></code> is an unsigned integral value. 1155 Saves to the archive or loads serialized state from the archive. 1156 The version number <code class="computeroutput"><span class="identifier">n</span></code> 1157 is the stored version when the object is loaded or the current 1158 version when the object is saved. 1159 </p> 1160 </td> 1161</tr></tbody> 1162</table></div> 1163</div> 1164<br class="table-break"><h5> 1165<a name="histogram.concepts.Transform.h2"></a> 1166 <span class="phrase"><a name="histogram.concepts.Transform.models"></a></span><a class="link" href="concepts.html#histogram.concepts.Transform.models">Models</a> 1167 </h5> 1168<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1169<li class="listitem"> 1170 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/transform/id.html" title="Struct id">boost::histogram::axis::transform::id</a></code> 1171 </li> 1172<li class="listitem"> 1173 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/transform/log.html" title="Struct log">boost::histogram::axis::transform::log</a></code> 1174 </li> 1175<li class="listitem"> 1176 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/transform/sqrt.html" title="Struct sqrt">boost::histogram::axis::transform::sqrt</a></code> 1177 </li> 1178<li class="listitem"> 1179 <code class="computeroutput"><a class="link" href="../boost/histogram/axis/transform/pow.html" title="Struct pow">boost::histogram::axis::transform::pow</a></code> 1180 </li> 1181</ul></div> 1182</div> 1183<div class="section"> 1184<div class="titlepage"><div><div><h3 class="title"> 1185<a name="histogram.concepts.Storage"></a><a class="link" href="concepts.html#histogram.concepts.Storage" title="Storage">Storage</a> 1186</h3></div></div></div> 1187<p> 1188 A <span class="bold"><strong>Storage</strong></span> handles memory for the bin counters 1189 and provides a uniform vector-like interface for accessing cell values for 1190 reading and writing. Must be <a href="https://en.cppreference.com/w/cpp/named_req/DefaultConstructible" target="_top">DefaultConstructible</a>, 1191 <a href="https://en.cppreference.com/w/cpp/named_req/CopyConstructible" target="_top">CopyConstructible</a>, 1192 and <a href="https://en.cppreference.com/w/cpp/named_req/CopyAssignable" target="_top">CopyAssignable</a>. 1193 </p> 1194<h5> 1195<a name="histogram.concepts.Storage.h0"></a> 1196 <span class="phrase"><a name="histogram.concepts.Storage.required_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Storage.required_features">Required 1197 features</a> 1198 </h5> 1199<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1200<li class="listitem"> 1201 <code class="computeroutput"><span class="identifier">S</span></code> is a type meeting the 1202 requirements of <span class="bold"><strong>Storage</strong></span> 1203 </li> 1204<li class="listitem"> 1205 <code class="computeroutput"><span class="identifier">s</span></code> is a value of types 1206 <code class="computeroutput"><span class="identifier">S</span></code> 1207 </li> 1208<li class="listitem"> 1209 <code class="computeroutput"><span class="identifier">i</span></code> and <code class="computeroutput"><span class="identifier">n</span></code> 1210 are values of type <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span></code> 1211 </li> 1212<li class="listitem"> 1213 <code class="computeroutput"><span class="identifier">Alloc</span></code> is an allocator 1214 type for <code class="computeroutput"><span class="identifier">S</span></code> 1215 </li> 1216</ul></div> 1217<div class="table"> 1218<a name="histogram.concepts.Storage.valid_expressions"></a><p class="title"><b>Table 1.7. Valid expressions</b></p> 1219<div class="table-contents"><table class="table" summary="Valid expressions"> 1220<colgroup> 1221<col> 1222<col> 1223<col> 1224</colgroup> 1225<thead><tr> 1226<th> 1227 <p> 1228 Expression 1229 </p> 1230 </th> 1231<th> 1232 <p> 1233 Returns 1234 </p> 1235 </th> 1236<th> 1237 <p> 1238 Semantics, Pre/Post-conditions 1239 </p> 1240 </th> 1241</tr></thead> 1242<tbody> 1243<tr> 1244<td> 1245 <p> 1246 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">value_type</span></code> 1247 </p> 1248 </td> 1249<td> 1250 </td> 1251<td> 1252 <p> 1253 Cell element type, may be either an integral type, floating-point 1254 type, or a type meeting the requirements of <a class="link" href="concepts.html#histogram.concepts.Accumulator" title="Accumulator"><span class="bold"><strong>Accumulator</strong></span></a>. 1255 </p> 1256 </td> 1257</tr> 1258<tr> 1259<td> 1260 <p> 1261 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">reference</span></code> 1262 </p> 1263 </td> 1264<td> 1265 </td> 1266<td> 1267 <p> 1268 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">&</span></code> 1269 or a proxy class which acts like a reference. 1270 </p> 1271 </td> 1272</tr> 1273<tr> 1274<td> 1275 <p> 1276 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">const_reference</span></code> 1277 </p> 1278 </td> 1279<td> 1280 </td> 1281<td> 1282 <p> 1283 <code class="computeroutput"><span class="keyword">const</span> <span class="identifier">S</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">&</span></code> or a proxy class which acts 1284 like a const reference. Implicitly convertible to <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">value_type</span></code>. 1285 </p> 1286 </td> 1287</tr> 1288<tr> 1289<td> 1290 <p> 1291 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">iterator</span></code> 1292 </p> 1293 </td> 1294<td> 1295 </td> 1296<td> 1297 <p> 1298 Returns an STL-compliant iterator type which dereferences to <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">reference</span></code>. 1299 </p> 1300 </td> 1301</tr> 1302<tr> 1303<td> 1304 <p> 1305 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">const_iterator</span></code> 1306 </p> 1307 </td> 1308<td> 1309 </td> 1310<td> 1311 <p> 1312 Returns an STL-compliant iterator type which dereferences to <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">const_reference</span></code>. 1313 </p> 1314 </td> 1315</tr> 1316<tr> 1317<td> 1318 <p> 1319 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">has_threading_support</span></code> 1320 </p> 1321 </td> 1322<td> 1323 <p> 1324 bool 1325 </p> 1326 </td> 1327<td> 1328 <p> 1329 Static constexpr member. True, if storage supports parallel read-write 1330 access to all cells. False, if such parallel access would either 1331 cause data corruption or require synchronization so that effectively 1332 only one cell can be accessed at a time, making cell-access single-threaded. 1333 </p> 1334 </td> 1335</tr> 1336<tr> 1337<td> 1338 <p> 1339 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code> 1340 </p> 1341 </td> 1342<td> 1343 <p> 1344 <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span></code> 1345 </p> 1346 </td> 1347<td> 1348 <p> 1349 Const member function which returns the current number of cells 1350 in the storage. 1351 </p> 1352 </td> 1353</tr> 1354<tr> 1355<td> 1356 <p> 1357 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">reset</span><span class="special">(</span><span class="identifier">n</span><span class="special">)</span></code> 1358 </p> 1359 </td> 1360<td> 1361 </td> 1362<td> 1363 <p> 1364 Non-const member function which discards current cell values, changes 1365 storage size to <code class="computeroutput"><span class="identifier">n</span></code> 1366 and initializes all cells to the default-constructed state. 1367 </p> 1368 </td> 1369</tr> 1370<tr> 1371<td> 1372 <p> 1373 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">begin</span><span class="special">()</span></code> 1374 </p> 1375 </td> 1376<td> 1377 <p> 1378 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">iterator</span></code> 1379 </p> 1380 </td> 1381<td> 1382 <p> 1383 Non-const member function which returns the iterator to the first 1384 storage cell. 1385 </p> 1386 </td> 1387</tr> 1388<tr> 1389<td> 1390 <p> 1391 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">begin</span><span class="special">()</span></code> 1392 </p> 1393 </td> 1394<td> 1395 <p> 1396 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">const_iterator</span></code> 1397 </p> 1398 </td> 1399<td> 1400 <p> 1401 Likewise, but a const member function which returns the const_iterator. 1402 </p> 1403 </td> 1404</tr> 1405<tr> 1406<td> 1407 <p> 1408 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">end</span><span class="special">()</span></code> 1409 </p> 1410 </td> 1411<td> 1412 <p> 1413 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">iterator</span></code> 1414 </p> 1415 </td> 1416<td> 1417 <p> 1418 Member function which returns the iterator to the cell after the 1419 last valid storage cell. 1420 </p> 1421 </td> 1422</tr> 1423<tr> 1424<td> 1425 <p> 1426 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">end</span><span class="special">()</span></code> 1427 </p> 1428 </td> 1429<td> 1430 <p> 1431 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">const_iterator</span></code> 1432 </p> 1433 </td> 1434<td> 1435 <p> 1436 Likewise, but a const member function which returns the const_iterator. 1437 </p> 1438 </td> 1439</tr> 1440<tr> 1441<td> 1442 <p> 1443 <code class="computeroutput"><span class="identifier">s</span><span class="special">[</span><span class="identifier">i</span><span class="special">]</span></code> 1444 </p> 1445 </td> 1446<td> 1447 <p> 1448 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">reference</span></code> 1449 </p> 1450 </td> 1451<td> 1452 <p> 1453 Member function which returns a reference to the cell which is 1454 addressed by <code class="computeroutput"><span class="identifier">i</span></code>. 1455 The index <code class="computeroutput"><span class="identifier">i</span></code> must 1456 be valid: <code class="computeroutput"><span class="identifier">i</span> <span class="special"><</span> 1457 <span class="identifier">s</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span></code>. 1458 </p> 1459 </td> 1460</tr> 1461<tr> 1462<td> 1463 <p> 1464 <code class="computeroutput"><span class="identifier">s</span><span class="special">[</span><span class="identifier">i</span><span class="special">]</span></code> 1465 </p> 1466 </td> 1467<td> 1468 <p> 1469 <code class="computeroutput"><span class="identifier">S</span><span class="special">::</span><span class="identifier">const_reference</span></code> 1470 </p> 1471 </td> 1472<td> 1473 <p> 1474 Likewise, but a const member function which returns a const reference. 1475 </p> 1476 </td> 1477</tr> 1478<tr> 1479<td> 1480 <p> 1481 <code class="computeroutput"><span class="identifier">s</span> <span class="special">==</span> 1482 <span class="identifier">t</span></code> 1483 </p> 1484 </td> 1485<td> 1486 <p> 1487 <code class="computeroutput"><span class="keyword">bool</span></code> 1488 </p> 1489 </td> 1490<td> 1491 <p> 1492 <code class="computeroutput"><span class="identifier">t</span></code> is another value 1493 of a type which meets the requirements of <span class="bold"><strong>Storage</strong></span>. 1494 Returns <code class="computeroutput"><span class="keyword">true</span></code> if arguments 1495 have the same number of cells and all cells compare equal. Otherwise 1496 returns <code class="computeroutput"><span class="keyword">false</span></code>. 1497 </p> 1498 </td> 1499</tr> 1500<tr> 1501<td> 1502 <p> 1503 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">get_allocator</span><span class="special">()</span></code> 1504 </p> 1505 </td> 1506<td> 1507 <p> 1508 <code class="computeroutput"><span class="identifier">Alloc</span></code> 1509 </p> 1510 </td> 1511<td> 1512 <p> 1513 Const member function which returns the allocator used by <code class="computeroutput"><span class="identifier">S</span></code>. Must be omitted if <code class="computeroutput"><span class="identifier">S</span></code> does not use allocators. If 1514 this member function exists, also a special constructor must exist 1515 so that <code class="computeroutput"><span class="identifier">S</span><span class="special">(</span><span class="identifier">s</span><span class="special">.</span><span class="identifier">get_allocator</span><span class="special">())</span></code> 1516 is a valid expression. 1517 </p> 1518 </td> 1519</tr> 1520</tbody> 1521</table></div> 1522</div> 1523<br class="table-break"><h5> 1524<a name="histogram.concepts.Storage.h1"></a> 1525 <span class="phrase"><a name="histogram.concepts.Storage.optional_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Storage.optional_features">Optional 1526 features</a> 1527 </h5> 1528<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1529<li class="listitem"> 1530 <code class="computeroutput"><span class="identifier">S</span></code> is a type meeting the 1531 requirements of <span class="bold"><strong>Storage</strong></span> 1532 </li> 1533<li class="listitem"> 1534 <code class="computeroutput"><span class="identifier">s</span></code> is a value of types 1535 <code class="computeroutput"><span class="identifier">S</span></code> 1536 </li> 1537<li class="listitem"> 1538 <code class="computeroutput"><span class="identifier">x</span></code> is convertible to 1539 <code class="computeroutput"><span class="keyword">double</span></code> 1540 </li> 1541<li class="listitem"> 1542 <code class="computeroutput"><span class="identifier">ar</span></code> is a value of an archive 1543 with Boost.Serialization semantics 1544 </li> 1545</ul></div> 1546<div class="table"> 1547<a name="histogram.concepts.Storage.valid_expressions0"></a><p class="title"><b>Table 1.8. Valid expressions</b></p> 1548<div class="table-contents"><table class="table" summary="Valid expressions"> 1549<colgroup> 1550<col> 1551<col> 1552<col> 1553</colgroup> 1554<thead><tr> 1555<th> 1556 <p> 1557 Expression 1558 </p> 1559 </th> 1560<th> 1561 <p> 1562 Returns 1563 </p> 1564 </th> 1565<th> 1566 <p> 1567 Semantics, Pre/Post-conditions 1568 </p> 1569 </th> 1570</tr></thead> 1571<tbody> 1572<tr> 1573<td> 1574 <p> 1575 <code class="computeroutput"><span class="identifier">s</span> <span class="special">*=</span> 1576 <span class="identifier">x</span></code> 1577 </p> 1578 </td> 1579<td> 1580 <p> 1581 <code class="computeroutput"><span class="identifier">S</span><span class="special">&</span></code> 1582 </p> 1583 </td> 1584<td> 1585 <p> 1586 Scales all cell values by the factor <code class="computeroutput"><span class="identifier">x</span></code> 1587 and returns a reference to self. 1588 </p> 1589 </td> 1590</tr> 1591<tr> 1592<td> 1593 <p> 1594 <code class="computeroutput"><span class="identifier">s</span><span class="special">.</span><span class="identifier">serialize</span><span class="special">(</span><span class="identifier">ar</span><span class="special">,</span> 1595 <span class="identifier">n</span><span class="special">)</span></code> 1596 </p> 1597 </td> 1598<td> 1599 </td> 1600<td> 1601 <p> 1602 <code class="computeroutput"><span class="identifier">ar</span></code> is a value of 1603 an archive with Boost.Serialization semantics and <code class="computeroutput"><span class="identifier">n</span></code> is an unsigned integral value. 1604 Saves to the archive or loads serialized state from the archive. 1605 The version number <code class="computeroutput"><span class="identifier">n</span></code> 1606 is the stored version when the object is loaded or the current 1607 version when the object is saved. 1608 </p> 1609 </td> 1610</tr> 1611</tbody> 1612</table></div> 1613</div> 1614<br class="table-break"><h5> 1615<a name="histogram.concepts.Storage.h2"></a> 1616 <span class="phrase"><a name="histogram.concepts.Storage.models"></a></span><a class="link" href="concepts.html#histogram.concepts.Storage.models">Models</a> 1617 </h5> 1618<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1619<li class="listitem"> 1620 <code class="computeroutput"><a class="link" href="../boost/histogram/unlimited_storage.html" title="Class template unlimited_storage">boost::histogram::unlimited_storage</a></code> 1621 </li> 1622<li class="listitem"> 1623 <code class="computeroutput"><a class="link" href="../boost/histogram/storage_adaptor.html" title="Class template storage_adaptor">boost::histogram::storage_adaptor</a></code> 1624 </li> 1625<li class="listitem"> 1626 <code class="computeroutput"><a class="link" href="reference.html#boost.histogram.dense_storage">boost::histogram::dense_storage</a></code> 1627 </li> 1628<li class="listitem"> 1629 <code class="computeroutput"><a class="link" href="reference.html#boost.histogram.weight_storage">boost::histogram::weight_storage</a></code> 1630 </li> 1631<li class="listitem"> 1632 <code class="computeroutput"><a class="link" href="reference.html#boost.histogram.profile_storage">boost::histogram::profile_storage</a></code> 1633 </li> 1634<li class="listitem"> 1635 <code class="computeroutput"><a class="link" href="reference.html#boost.histogram.weighted_profile_storage">boost::histogram::weighted_profile_storage</a></code> 1636 </li> 1637</ul></div> 1638</div> 1639<div class="section"> 1640<div class="titlepage"><div><div><h3 class="title"> 1641<a name="histogram.concepts.Accumulator"></a><a class="link" href="concepts.html#histogram.concepts.Accumulator" title="Accumulator">Accumulator</a> 1642</h3></div></div></div> 1643<p> 1644 An <span class="bold"><strong>Accumulator</strong></span> is a functor which consumes 1645 the argument to update some internal state. Must be <a href="https://en.cppreference.com/w/cpp/named_req/DefaultConstructible" target="_top">DefaultConstructible</a>, 1646 <a href="https://en.cppreference.com/w/cpp/named_req/CopyConstructible" target="_top">CopyConstructible</a>, 1647 and <a href="https://en.cppreference.com/w/cpp/named_req/CopyAssignable" target="_top">CopyAssignable</a>. 1648 </p> 1649<h5> 1650<a name="histogram.concepts.Accumulator.h0"></a> 1651 <span class="phrase"><a name="histogram.concepts.Accumulator.required_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Accumulator.required_features">Required 1652 features</a> 1653 </h5> 1654<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1655<li class="listitem"> 1656 <code class="computeroutput"><span class="identifier">A</span></code> is a type meeting the 1657 requirements of <span class="bold"><strong>Accumulator</strong></span> 1658 </li> 1659<li class="listitem"> 1660 <code class="computeroutput"><span class="identifier">a</span></code> and <code class="computeroutput"><span class="identifier">b</span></code> 1661 are values of type <code class="computeroutput"><span class="identifier">A</span></code> 1662 </li> 1663<li class="listitem"> 1664 <code class="computeroutput"><span class="identifier">ts</span><span class="special">...</span></code> 1665 is a pack of values of arbitrary types 1666 </li> 1667</ul></div> 1668<div class="table"> 1669<a name="histogram.concepts.Accumulator.valid_expressions"></a><p class="title"><b>Table 1.9. Valid expressions</b></p> 1670<div class="table-contents"><table class="table" summary="Valid expressions"> 1671<colgroup> 1672<col> 1673<col> 1674<col> 1675</colgroup> 1676<thead><tr> 1677<th> 1678 <p> 1679 Expression 1680 </p> 1681 </th> 1682<th> 1683 <p> 1684 Returns 1685 </p> 1686 </th> 1687<th> 1688 <p> 1689 Semantics, Pre/Post-conditions 1690 </p> 1691 </th> 1692</tr></thead> 1693<tbody> 1694<tr> 1695<td> 1696 <p> 1697 <code class="computeroutput"><span class="identifier">a</span><span class="special">(</span><span class="identifier">ts</span><span class="special">...)</span></code> 1698 or <code class="computeroutput"><span class="special">++</span><span class="identifier">a</span></code> 1699 </p> 1700 </td> 1701<td> 1702 </td> 1703<td> 1704 <p> 1705 Either a call operator accepting a fixed number of arguments must 1706 be implemented, or the pre-increment operator. The call operator 1707 may not be templated and not overloaded, except to support weights 1708 as described under optional features. 1709 </p> 1710 </td> 1711</tr> 1712<tr> 1713<td> 1714 <p> 1715 <code class="computeroutput"><span class="identifier">a</span> <span class="special">==</span> 1716 <span class="identifier">b</span></code> 1717 </p> 1718 </td> 1719<td> 1720 <p> 1721 <code class="computeroutput"><span class="keyword">bool</span></code> 1722 </p> 1723 </td> 1724<td> 1725 <p> 1726 Returns <code class="computeroutput"><span class="keyword">true</span></code> if all 1727 state variables compare equal. Otherwise returns <code class="computeroutput"><span class="keyword">false</span></code>. 1728 </p> 1729 </td> 1730</tr> 1731<tr> 1732<td> 1733 <p> 1734 <code class="computeroutput"><span class="identifier">a</span> <span class="special">!=</span> 1735 <span class="identifier">b</span></code> 1736 </p> 1737 </td> 1738<td> 1739 <p> 1740 <code class="computeroutput"><span class="keyword">bool</span></code> 1741 </p> 1742 </td> 1743<td> 1744 <p> 1745 Must be implemented if <code class="computeroutput"><span class="identifier">a</span> 1746 <span class="special">==</span> <span class="identifier">b</span></code> 1747 is implemented and must be equal to <code class="computeroutput"><span class="special">!(</span><span class="identifier">a</span> <span class="special">==</span> 1748 <span class="identifier">b</span><span class="special">)</span></code>. 1749 </p> 1750 </td> 1751</tr> 1752</tbody> 1753</table></div> 1754</div> 1755<br class="table-break"><h5> 1756<a name="histogram.concepts.Accumulator.h1"></a> 1757 <span class="phrase"><a name="histogram.concepts.Accumulator.optional_features"></a></span><a class="link" href="concepts.html#histogram.concepts.Accumulator.optional_features">Optional 1758 features</a> 1759 </h5> 1760<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1761<li class="listitem"> 1762 <code class="computeroutput"><span class="identifier">A</span></code> is a type meeting the 1763 requirements of <span class="bold"><strong>Accumulator</strong></span> 1764 </li> 1765<li class="listitem"> 1766 <code class="computeroutput"><span class="identifier">a</span></code> and <code class="computeroutput"><span class="identifier">b</span></code> 1767 are values of type <code class="computeroutput"><span class="identifier">A</span></code> 1768 </li> 1769<li class="listitem"> 1770 <code class="computeroutput"><span class="identifier">w</span></code> is a value of type 1771 <code class="computeroutput"><a class="link" href="../boost/histogram/weight_type.html" title="Struct template weight_type">boost::histogram::weight_type</a></code>, 1772 where <code class="computeroutput"><span class="identifier">T</span></code> is a number type 1773 </li> 1774<li class="listitem"> 1775 <code class="computeroutput"><span class="identifier">ts</span><span class="special">...</span></code> 1776 is a pack of values of arbitrary types 1777 </li> 1778<li class="listitem"> 1779 <code class="computeroutput"><span class="identifier">v</span></code> is a number value (integral 1780 or floating point) 1781 </li> 1782</ul></div> 1783<div class="table"> 1784<a name="histogram.concepts.Accumulator.valid_expressions0"></a><p class="title"><b>Table 1.10. Valid expressions</b></p> 1785<div class="table-contents"><table class="table" summary="Valid expressions"> 1786<colgroup> 1787<col> 1788<col> 1789<col> 1790</colgroup> 1791<thead><tr> 1792<th> 1793 <p> 1794 Expression 1795 </p> 1796 </th> 1797<th> 1798 <p> 1799 Return 1800 </p> 1801 </th> 1802<th> 1803 <p> 1804 Semantics, Pre/Post-conditions 1805 </p> 1806 </th> 1807</tr></thead> 1808<tbody> 1809<tr> 1810<td> 1811 <p> 1812 <code class="computeroutput"><span class="identifier">a</span> <span class="special">+=</span> 1813 <span class="identifier">v</span></code> or <code class="computeroutput"><span class="identifier">a</span><span class="special">(</span><span class="identifier">w</span><span class="special">,</span> <span class="identifier">ts</span><span class="special">...)</span></code> 1814 </p> 1815 </td> 1816<td> 1817 </td> 1818<td> 1819 <p> 1820 Does a weighted fill of the accumulator. Use this to implement 1821 weight support for an accumulator that is normally filled with 1822 <code class="computeroutput"><span class="special">++</span><span class="identifier">a</span></code> 1823 or <code class="computeroutput"><span class="identifier">a</span><span class="special">(</span><span class="identifier">ts</span><span class="special">...)</span></code>, 1824 respectively. Only the corresponding matching form may be implemented: 1825 <code class="computeroutput"><span class="identifier">a</span> <span class="special">+=</span> 1826 <span class="identifier">v</span></code> for <code class="computeroutput"><span class="special">++</span><span class="identifier">a</span></code>, <code class="computeroutput"><span class="identifier">a</span><span class="special">(</span><span class="identifier">w</span><span class="special">,</span> <span class="identifier">ts</span><span class="special">...)</span></code> for <code class="computeroutput"><span class="identifier">a</span><span class="special">(</span><span class="identifier">ts</span><span class="special">...)</span></code>. The implementations may not 1827 be templated and not overloaded. 1828 </p> 1829 </td> 1830</tr> 1831<tr> 1832<td> 1833 <p> 1834 <code class="computeroutput"><span class="identifier">a</span> <span class="special">+=</span> 1835 <span class="identifier">b</span></code> 1836 </p> 1837 </td> 1838<td> 1839 <p> 1840 <code class="computeroutput"><span class="identifier">A</span><span class="special">&</span></code> 1841 </p> 1842 </td> 1843<td> 1844 <p> 1845 Adds a second accumulator <code class="computeroutput"><span class="identifier">b</span></code> 1846 of type <code class="computeroutput"><span class="identifier">A</span></code>. The 1847 result must be the same as if <code class="computeroutput"><span class="identifier">a</span></code> 1848 had been filled with all arguments of <code class="computeroutput"><span class="identifier">b</span></code>. 1849 </p> 1850 </td> 1851</tr> 1852<tr> 1853<td> 1854 <p> 1855 <code class="computeroutput"><span class="identifier">a</span> <span class="special">*=</span> 1856 <span class="identifier">x</span></code> 1857 </p> 1858 </td> 1859<td> 1860 <p> 1861 <code class="computeroutput"><span class="identifier">A</span><span class="special">&</span></code> 1862 </p> 1863 </td> 1864<td> 1865 <p> 1866 Scales the accumulator state by the real value <code class="computeroutput"><span class="identifier">x</span></code>. 1867 The result must be the same as if <code class="computeroutput"><span class="identifier">a</span></code> 1868 had been filled with all arguments scaled by <code class="computeroutput"><span class="identifier">x</span></code>. 1869 </p> 1870 </td> 1871</tr> 1872<tr> 1873<td> 1874 <p> 1875 <code class="computeroutput"><span class="identifier">os</span> <span class="special"><<</span> 1876 <span class="identifier">a</span></code> 1877 </p> 1878 </td> 1879<td> 1880 <p> 1881 <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> 1882 <span class="identifier">Traits</span><span class="special">>&</span></code> 1883 </p> 1884 </td> 1885<td> 1886 <p> 1887 <code class="computeroutput"><span class="identifier">os</span></code> is a value of 1888 type <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special"><</span><span class="identifier">CharT</span><span class="special">,</span> 1889 <span class="identifier">Traits</span><span class="special">></span></code>. 1890 Streams a text representation of the axis. May not mutate <code class="computeroutput"><span class="identifier">a</span></code>. 1891 </p> 1892 </td> 1893</tr> 1894<tr> 1895<td> 1896 <p> 1897 <code class="computeroutput"><span class="identifier">a</span><span class="special">.</span><span class="identifier">serialize</span><span class="special">(</span><span class="identifier">ar</span><span class="special">,</span> 1898 <span class="identifier">n</span><span class="special">)</span></code> 1899 </p> 1900 </td> 1901<td> 1902 </td> 1903<td> 1904 <p> 1905 <code class="computeroutput"><span class="identifier">ar</span></code> is a value of 1906 an archive with Boost.Serialization semantics and <code class="computeroutput"><span class="identifier">n</span></code> is an unsigned integral value. 1907 Saves to the archive or loads serialized state from the archive. 1908 The version number <code class="computeroutput"><span class="identifier">n</span></code> 1909 is the stored version when the object is loaded or the current 1910 version when the object is saved. 1911 </p> 1912 </td> 1913</tr> 1914</tbody> 1915</table></div> 1916</div> 1917<br class="table-break"><h5> 1918<a name="histogram.concepts.Accumulator.h2"></a> 1919 <span class="phrase"><a name="histogram.concepts.Accumulator.models"></a></span><a class="link" href="concepts.html#histogram.concepts.Accumulator.models">Models</a> 1920 </h5> 1921<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 1922<li class="listitem"> 1923 <code class="computeroutput"><a class="link" href="../boost/histogram/accumulators/sum.html" title="Class template sum">boost::histogram::accumulators::sum</a></code> 1924 </li> 1925<li class="listitem"> 1926 <code class="computeroutput"><a class="link" href="../boost/histogram/accumulators/weighted_sum.html" title="Class template weighted_sum">boost::histogram::accumulators::weighted_sum</a></code> 1927 </li> 1928<li class="listitem"> 1929 <code class="computeroutput"><a class="link" href="../boost/histogram/accumulators/mean.html" title="Class template mean">boost::histogram::accumulators::mean</a></code> 1930 </li> 1931<li class="listitem"> 1932 <code class="computeroutput"><a class="link" href="../boost/histogram/accumulators/weighted_mean.html" title="Class template weighted_mean">boost::histogram::accumulators::weighted_mean</a></code> 1933 </li> 1934</ul></div> 1935</div> 1936</div> 1937<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 1938<td align="left"></td> 1939<td align="right"><div class="copyright-footer">Copyright © 2016-2019 Hans 1940 Dembinski<p> 1941 Distributed under the Boost Software License, Version 1.0. (See accompanying 1942 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 1943 </p> 1944</div></td> 1945</tr></table> 1946<hr> 1947<div class="spirit-nav"> 1948<a accesskey="p" href="benchmarks.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="reference.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 1949</div> 1950</body> 1951</html> 1952
