1 // Copyright 2020 Hans Dembinski
2 //
3 // Distributed under the Boost Software License, Version 1.0.
4 // (See accompanying file LICENSE_1_0.txt
5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
6
7 //[ guide_histogram_in_api
8
9 #include <boost/histogram.hpp>
10 #include <cassert>
11
12 // function accepts any histogram and returns a copy
13 template <class Axes, class Storage>
any_histogram(boost::histogram::histogram<Axes,Storage> & h)14 boost::histogram::histogram<Axes, Storage> any_histogram(
15 boost::histogram::histogram<Axes, Storage>& h) {
16 return h;
17 }
18
19 // function only accepts histograms with fixed axis types and returns a copy
20 template <class Storage, class... Axes>
only_static_histogram(boost::histogram::histogram<std::tuple<Axes...>,Storage> & h)21 boost::histogram::histogram<std::tuple<Axes...>, Storage> only_static_histogram(
22 boost::histogram::histogram<std::tuple<Axes...>, Storage>& h) {
23 return h;
24 }
25
26 // function only accepts histograms with dynamic axis types and returns a copy
27 template <class Storage, class... Axes>
28 boost::histogram::histogram<std::vector<boost::histogram::axis::variant<Axes...>>,
29 Storage>
only_dynamic_histogram(boost::histogram::histogram<std::vector<boost::histogram::axis::variant<Axes...>>,Storage> & h)30 only_dynamic_histogram(
31 boost::histogram::histogram<std::vector<boost::histogram::axis::variant<Axes...>>,
32 Storage>& h) {
33 return h;
34 }
35
main()36 int main() {
37 using namespace boost::histogram;
38
39 auto histogram_with_static_axes = make_histogram(axis::regular<>(10, 0, 1));
40
41 using axis_variant = axis::variant<axis::regular<>, axis::integer<>>;
42 std::vector<axis_variant> axes;
43 axes.emplace_back(axis::regular<>(5, 0, 1));
44 axes.emplace_back(axis::integer<>(0, 1));
45 auto histogram_with_dynamic_axes = make_histogram(axes);
46
47 assert(any_histogram(histogram_with_static_axes) == histogram_with_static_axes);
48 assert(any_histogram(histogram_with_dynamic_axes) == histogram_with_dynamic_axes);
49 assert(only_static_histogram(histogram_with_static_axes) == histogram_with_static_axes);
50 assert(only_dynamic_histogram(histogram_with_dynamic_axes) ==
51 histogram_with_dynamic_axes);
52
53 // does not compile: only_static_histogram(histogram_with_dynamic_axes)
54 // does not compile: only_dynamic_histogram(histogram_with_static_axes)
55 }
56
57 //]
58