1.. Metafunctions/Comparisons//less |10 2 3less 4==== 5 6Synopsis 7-------- 8 9.. parsed-literal:: 10 11 template< 12 typename T1 13 , typename T2 14 > 15 struct less 16 { 17 typedef |unspecified| type; 18 }; 19 20 21 22Description 23----------- 24 25Returns a true-valued |Integral Constant| if ``T1`` is less than ``T2``. 26 27 28Header 29------ 30 31.. parsed-literal:: 32 33 #include <boost/mpl/less.hpp> 34 #include <boost/mpl/comparison.hpp> 35 36 37Model of 38-------- 39 40|Numeric Metafunction| 41 42 43Parameters 44---------- 45 46+---------------+---------------------------+-----------------------------------------------+ 47| Parameter | Requirement | Description | 48+===============+===========================+===============================================+ 49| ``T1``, ``T2``| |Integral Constant| | Operation's arguments. | 50+---------------+---------------------------+-----------------------------------------------+ 51 52|Note:| |numeric metafunction note| |-- end note| 53 54 55Expression semantics 56-------------------- 57 58 59For any |Integral Constant|\ s ``c1`` and ``c2``: 60 61.. parsed-literal:: 62 63 typedef less<c1,c2>::type r; 64 65:Return type: 66 |Integral Constant|. 67 68:Semantics: 69 Equivalent to 70 71 .. parsed-literal:: 72 73 typedef bool_< (c1::value < c2::value) > r; 74 75 76.. .......................................................................... 77 78.. parsed-literal:: 79 80 typedef less<c1,c2> r; 81 82:Return type: 83 |Integral Constant|. 84 85:Semantics: 86 Equivalent to 87 88 .. parsed-literal:: 89 90 struct r : less<c1,c2>::type {}; 91 92 93 94Complexity 95---------- 96 97Amortized constant time. 98 99 100Example 101------- 102 103.. parsed-literal:: 104 105 BOOST_MPL_ASSERT(( less< int_<0>, int_<10> > )); 106 BOOST_MPL_ASSERT_NOT(( less< long_<10>, int_<0> > )); 107 BOOST_MPL_ASSERT_NOT(( less< long_<10>, int_<10> > )); 108 109 110See also 111-------- 112 113|Comparisons|, |Numeric Metafunction|, |numeric_cast|, |less_equal|, |greater|, |equal| 114 115 116.. copyright:: Copyright � 2001-2009 Aleksey Gurtovoy and David Abrahams 117 Distributed under the Boost Software License, Version 1.0. (See accompanying 118 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 119