1 | // Copyright John Maddock 2016. |
2 | // Use, modification and distribution are subject to the |
3 | // Boost Software License, Version 1.0. (See accompanying file |
4 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
5 | |
6 | #ifndef BOOST_MATH_TOOLS_CONVERT_FROM_STRING_INCLUDED |
7 | #define BOOST_MATH_TOOLS_CONVERT_FROM_STRING_INCLUDED |
8 | |
9 | #ifdef _MSC_VER |
10 | #pragma once |
11 | #endif |
12 | |
13 | #include <boost/type_traits/is_constructible.hpp> |
14 | #include <boost/type_traits/conditional.hpp> |
15 | #include <boost/lexical_cast.hpp> |
16 | |
17 | namespace boost{ namespace math{ namespace tools{ |
18 | |
19 | template <class T> |
20 | struct convert_from_string_result |
21 | { |
22 | typedef typename boost::conditional<boost::is_constructible<T, const char*>::value, const char*, T>::type type; |
23 | }; |
24 | |
25 | template <class Real> |
26 | Real convert_from_string(const char* p, const boost::false_type&) |
27 | { |
28 | #ifdef BOOST_MATH_NO_LEXICAL_CAST |
29 | // This function should not compile, we don't have the necessary functionality to support it: |
30 | BOOST_STATIC_ASSERT(sizeof(Real) == 0); |
31 | #else |
32 | return boost::lexical_cast<Real>(p); |
33 | #endif |
34 | } |
35 | template <class Real> |
36 | BOOST_CONSTEXPR const char* convert_from_string(const char* p, const boost::true_type&) BOOST_NOEXCEPT |
37 | { |
38 | return p; |
39 | } |
40 | template <class Real> |
41 | BOOST_CONSTEXPR typename convert_from_string_result<Real>::type convert_from_string(const char* p) BOOST_NOEXCEPT_IF((boost::is_constructible<Real, const char*>::value)) |
42 | { |
43 | return convert_from_string<Real>(p, boost::is_constructible<Real, const char*>()); |
44 | } |
45 | |
46 | } // namespace tools |
47 | } // namespace math |
48 | } // namespace boost |
49 | |
50 | #endif // BOOST_MATH_TOOLS_CONVERT_FROM_STRING_INCLUDED |
51 | |
52 | |