mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-31 12:30:06 +00:00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91425 91177308-0d34-0410-b5e6-96231b3b80d8
127 lines
4.4 KiB
C++
127 lines
4.4 KiB
C++
//===- llvm/Support/type_traits.h - Simplfied type traits -------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file provides a template class that determines if a type is a class or
|
|
// not. The basic mechanism, based on using the pointer to member function of
|
|
// a zero argument to a function was "boosted" from the boost type_traits
|
|
// library. See http://www.boost.org/ for all the gory details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SUPPORT_TYPE_TRAITS_H
|
|
#define LLVM_SUPPORT_TYPE_TRAITS_H
|
|
|
|
#include <utility>
|
|
|
|
// This is actually the conforming implementation which works with abstract
|
|
// classes. However, enough compilers have trouble with it that most will use
|
|
// the one in boost/type_traits/object_traits.hpp. This implementation actually
|
|
// works with VC7.0, but other interactions seem to fail when we use it.
|
|
|
|
namespace llvm {
|
|
|
|
namespace dont_use
|
|
{
|
|
// These two functions should never be used. They are helpers to
|
|
// the is_class template below. They cannot be located inside
|
|
// is_class because doing so causes at least GCC to think that
|
|
// the value of the "value" enumerator is not constant. Placing
|
|
// them out here (for some strange reason) allows the sizeof
|
|
// operator against them to magically be constant. This is
|
|
// important to make the is_class<T>::value idiom zero cost. it
|
|
// evaluates to a constant 1 or 0 depending on whether the
|
|
// parameter T is a class or not (respectively).
|
|
template<typename T> char is_class_helper(void(T::*)());
|
|
template<typename T> double is_class_helper(...);
|
|
}
|
|
|
|
template <typename T>
|
|
struct is_class
|
|
{
|
|
// is_class<> metafunction due to Paul Mensonides (leavings@attbi.com). For
|
|
// more details:
|
|
// http://groups.google.com/groups?hl=en&selm=000001c1cc83%24e154d5e0%247772e50c%40c161550a&rnum=1
|
|
public:
|
|
enum { value = sizeof(char) == sizeof(dont_use::is_class_helper<T>(0)) };
|
|
};
|
|
|
|
|
|
/// isPodLike - This is a type trait that is used to determine whether a given
|
|
/// type can be copied around with memcpy instead of running ctors etc.
|
|
template <typename T>
|
|
struct isPodLike {
|
|
// If we don't know anything else, we can (at least) assume that all non-class
|
|
// types are PODs.
|
|
static const bool value = !is_class<T>::value;
|
|
};
|
|
|
|
// std::pair's are pod-like if their elements are.
|
|
template<typename T, typename U>
|
|
struct isPodLike<std::pair<T, U> > {
|
|
static const bool value = isPodLike<T>::value & isPodLike<U>::value;
|
|
};
|
|
|
|
|
|
/// \brief Metafunction that determines whether the two given types are
|
|
/// equivalent.
|
|
template<typename T, typename U>
|
|
struct is_same {
|
|
static const bool value = false;
|
|
};
|
|
|
|
template<typename T>
|
|
struct is_same<T, T> {
|
|
static const bool value = true;
|
|
};
|
|
|
|
// enable_if_c - Enable/disable a template based on a metafunction
|
|
template<bool Cond, typename T = void>
|
|
struct enable_if_c {
|
|
typedef T type;
|
|
};
|
|
|
|
template<typename T> struct enable_if_c<false, T> { };
|
|
|
|
// enable_if - Enable/disable a template based on a metafunction
|
|
template<typename Cond, typename T = void>
|
|
struct enable_if : public enable_if_c<Cond::value, T> { };
|
|
|
|
namespace dont_use {
|
|
template<typename Base> char base_of_helper(const volatile Base*);
|
|
template<typename Base> double base_of_helper(...);
|
|
}
|
|
|
|
/// is_base_of - Metafunction to determine whether one type is a base class of
|
|
/// (or identical to) another type.
|
|
template<typename Base, typename Derived>
|
|
struct is_base_of {
|
|
static const bool value
|
|
= is_class<Base>::value && is_class<Derived>::value &&
|
|
sizeof(char) == sizeof(dont_use::base_of_helper<Base>((Derived*)0));
|
|
};
|
|
|
|
// remove_pointer - Metafunction to turn Foo* into Foo. Defined in
|
|
// C++0x [meta.trans.ptr].
|
|
template <typename T> struct remove_pointer { typedef T type; };
|
|
template <typename T> struct remove_pointer<T*> { typedef T type; };
|
|
template <typename T> struct remove_pointer<T*const> { typedef T type; };
|
|
template <typename T> struct remove_pointer<T*volatile> { typedef T type; };
|
|
template <typename T> struct remove_pointer<T*const volatile> {
|
|
typedef T type; };
|
|
|
|
template <bool, typename T, typename F>
|
|
struct conditional { typedef T type; };
|
|
|
|
template <typename T, typename F>
|
|
struct conditional<false, T, F> { typedef F type; };
|
|
|
|
}
|
|
|
|
#endif
|