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forked from boostorg/mp11

Make mp_for_each constexpr under C++14

This commit is contained in:
Peter Dimov
2017-05-31 23:44:24 +03:00
parent 3cce995877
commit b8bbd279b2
3 changed files with 70 additions and 19 deletions

View File

@@ -9,10 +9,17 @@
// http://www.boost.org/LICENSE_1_0.txt
#include <boost/mp11/integral.hpp>
#include <boost/config.hpp>
#include <type_traits>
#include <utility>
#include <cassert>
#if !defined( BOOST_NO_CXX14_CONSTEXPR )
# define BOOST_MP11_CONSTEXPR14 constexpr
#else
# define BOOST_MP11_CONSTEXPR14
#endif
namespace boost
{
namespace mp11
@@ -23,7 +30,7 @@ namespace detail
template<std::size_t N> struct mp_for_index_impl_
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -55,7 +62,7 @@ template<> struct mp_for_index_impl_<0>
template<> struct mp_for_index_impl_<1>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
return std::forward<F>(f)( mp_size_t<K+0>() );
}
@@ -63,7 +70,7 @@ template<> struct mp_for_index_impl_<1>
template<> struct mp_for_index_impl_<2>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -75,7 +82,7 @@ template<> struct mp_for_index_impl_<2>
template<> struct mp_for_index_impl_<3>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -88,7 +95,7 @@ template<> struct mp_for_index_impl_<3>
template<> struct mp_for_index_impl_<4>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -102,7 +109,7 @@ template<> struct mp_for_index_impl_<4>
template<> struct mp_for_index_impl_<5>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -117,7 +124,7 @@ template<> struct mp_for_index_impl_<5>
template<> struct mp_for_index_impl_<6>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -133,7 +140,7 @@ template<> struct mp_for_index_impl_<6>
template<> struct mp_for_index_impl_<7>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -150,7 +157,7 @@ template<> struct mp_for_index_impl_<7>
template<> struct mp_for_index_impl_<8>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -168,7 +175,7 @@ template<> struct mp_for_index_impl_<8>
template<> struct mp_for_index_impl_<9>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -187,7 +194,7 @@ template<> struct mp_for_index_impl_<9>
template<> struct mp_for_index_impl_<10>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -207,7 +214,7 @@ template<> struct mp_for_index_impl_<10>
template<> struct mp_for_index_impl_<11>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -228,7 +235,7 @@ template<> struct mp_for_index_impl_<11>
template<> struct mp_for_index_impl_<12>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -250,7 +257,7 @@ template<> struct mp_for_index_impl_<12>
template<> struct mp_for_index_impl_<13>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -273,7 +280,7 @@ template<> struct mp_for_index_impl_<13>
template<> struct mp_for_index_impl_<14>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -297,7 +304,7 @@ template<> struct mp_for_index_impl_<14>
template<> struct mp_for_index_impl_<15>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -322,7 +329,7 @@ template<> struct mp_for_index_impl_<15>
template<> struct mp_for_index_impl_<16>
{
template<std::size_t K, class F> static decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
template<std::size_t K, class F> static BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) call( std::size_t i, F && f )
{
switch( i )
{
@@ -348,17 +355,19 @@ template<> struct mp_for_index_impl_<16>
} // namespace detail
template<std::size_t N, class F> inline decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) mp_for_index( std::size_t i, F && f )
template<std::size_t N, class F> inline BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) mp_for_index( std::size_t i, F && f )
{
assert( i < N );
return detail::mp_for_index_impl_<N>::template call<0>( i, std::forward<F>(f) );
}
template<class N, class F> inline decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) mp_for_index( std::size_t i, F && f )
template<class N, class F> inline BOOST_MP11_CONSTEXPR14 decltype(std::declval<F>()(std::declval<mp_size_t<0>>())) mp_for_index( std::size_t i, F && f )
{
return mp_for_index<N::value>( i, std::forward<F>(f) );
}
#undef BOOST_MP11_CONSTEXPR14
} // namespace mp11
} // namespace boost

View File

@@ -72,6 +72,7 @@ run mp_for_each.cpp : : : $(REQ) ;
run mp_insert.cpp : : : $(REQ) ;
run mp_erase.cpp : : : $(REQ) ;
run mp_for_index.cpp : : : $(REQ) ;
run mp_for_index_cx.cpp : : : $(REQ) ;
# integral
run integral.cpp : : : $(REQ) ;

41
test/mp_for_index_cx.cpp Normal file
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@@ -0,0 +1,41 @@
// Copyright 2017 Peter Dimov.
//
// Distributed under the Boost Software License, Version 1.0.
//
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
#include <boost/config.hpp>
#if defined( BOOST_NO_CXX14_CONSTEXPR )
int main() {}
#else
#include <boost/mp11/algorithm.hpp>
#include <boost/core/lightweight_test.hpp>
#include <boost/config.hpp>
#include <boost/detail/workaround.hpp>
using boost::mp11::mp_size_t;
using boost::mp11::mp_for_index;
struct F
{
template<std::size_t I> constexpr std::size_t operator()( mp_size_t<I> ) const
{
return I;
}
};
#define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
int main()
{
constexpr std::size_t i = mp_for_index<64>( 57, F{} );
STATIC_ASSERT( i == 57 );
}
#endif