shortened names of new macros, improved comments

[SVN r18306]
This commit is contained in:
Gennaro Prota
2003-04-24 15:01:20 +00:00
parent 7fa91feb00
commit 767ec48375

View File

@ -337,67 +337,71 @@ namespace std {
# define BOOST_DEDUCED_TYPENAME
#endif
// BOOST_[APPEND_]TEMPLATE_EXPLICITLY_SPECIFIED_[NON_]TYPE macros -------------//
// BOOST_[APPEND_]EXPLICIT_TEMPLATE_[NON_]TYPE macros --------------------------//
//
// Some compilers have problems with function templates whose
// template parameters don't appear in the function parameter list.
//
// Basically they just link one instantiation of the template in
// the final executable.
// template parameters don't appear in the function parameter
// list (basically they just link one instantiation of the
// template in the final executable). These macros provide a
// uniform way to cope with the problem with no effects on the
// calling syntax.
// Example:
//
// #include <iostream>
// #include <ostream>
// #include <typeinfo>
//
// template <int n>
// void f() { std::cout << n << '\n'; }
// void f() { std::cout << n << ' '; }
//
// template <typename T>
// void g() { std::cout << typeid(T).name() << ' '; }
//
// int main() {
// f<1>();
// f<2>();
// f<1>();
// f<2>();
//
// g<int>();
// g<double>();
// }
//
// OUTPUT is:
// With VC++ 6.0 the output is:
//
// 2
// 2
// 2 2 double double
//
// Write the definition of f as
// To fix it, write
//
// template <int n>
// void f(BOOST_TEMPLATE_EXPLICITLY_SPECIFIED_NON_TYPE(int, n))
// { std::cout << n << '\n'; }
// template <int n>
// void f(BOOST_EXPLICIT_TEMPLATE_NON_TYPE(int, n)) { ... }
//
// template <typename T>
// void g(BOOST_EXPLICIT_TEMPLATE_TYPE(T)) { ... }
//
#if defined BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS
# include "boost/type.hpp"
# include "boost/non_type.hpp"
# include "boost/type.hpp"
# include "boost/non_type.hpp"
// For type parameters
#define BOOST_TEMPLATE_EXPLICITLY_SPECIFIED_TYPE(t) \
boost::type<t>* = 0
#define BOOST_APPEND_TEMPLATE_EXPLICITLY_SPECIFIED_TYPE(t) \
, BOOST_TEMPLATE_EXPLICITLY_SPECIFIED_TYPE(t)
// For non-type parameters
//
#define BOOST_TEMPLATE_EXPLICITLY_SPECIFIED_NON_TYPE(t, v) \
boost::non_type<t, v>* = 0
#define BOOST_APPEND_TEMPLATE_EXPLICITLY_SPECIFIED_NON_TYPE(t, v) \
, BOOST_TEMPLATE_EXPLICITLY_SPECIFIED_NON_TYPE(t, v)
# define BOOST_EXPLICIT_TEMPLATE_TYPE(t) boost::type<t>* = 0
# define BOOST_EXPLICIT_TEMPLATE_NON_TYPE(t, v) boost::non_type<t, v>* = 0
# define BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE(t) \
, BOOST_EXPLICIT_TEMPLATE_TYPE(t)
# define BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(t, v) \
, BOOST_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
#else
// no workaround needed: expand to nothing
#define BOOST_TEMPLATE_EXPLICITLY_SPECIFIED_TYPE(t)
#define BOOST_APPEND_TEMPLATE_EXPLICITLY_SPECIFIED_TYPE(t)
# define BOOST_EXPLICIT_TEMPLATE_TYPE(t)
# define BOOST_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
#define BOOST_TEMPLATE_EXPLICITLY_SPECIFIED_NON_TYPE(t, v)
#define BOOST_APPEND_TEMPLATE_EXPLICITLY_SPECIFIED_NON_TYPE(t, v)
# define BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE(t)
# define BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
#endif // defined BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS