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Add detection support for single argument construct and destroy

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This commit is contained in:
Glen Fernandes
2022-03-12 01:06:00 -05:00
parent f326683d42
commit c4deb479fd
3 changed files with 106 additions and 49 deletions
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135
include/boost/core/allocator_access.hpp
View File

@ -1,5 +1,5 @@
/*
Copyright 2020-2021 Glen Joseph Fernandes
Copyright 2020-2022 Glen Joseph Fernandes
(glenjofe@gmail.com)
Distributed under the Boost Software License, Version 1.0.
@ -427,9 +427,72 @@ allocator_allocate(A& a, typename allocator_size_type<A>::type n,
}
#endif
namespace detail {
#if defined(BOOST_NO_CXX11_ALLOCATOR)
template<class T, T>
struct alloc_no {
char x, y;
};
template<class A, class T>
class alloc_has_construct {
template<class O>
static alloc_no<void(O::*)(T*), &O::construct>
check(int);
template<class O>
static alloc_no<void(O::*)(T*) const, &O::construct>
check(int);
template<class O>
static alloc_no<void(*)(T*), &O::construct>
check(int);
template<class>
static char check(long);
public:
static const bool value = sizeof(check<A>(0)) > 1;
};
#else
template<class A, class T, class... Args>
class alloc_has_construct {
template<class O>
static auto check(int)
-> alloc_no<decltype(std::declval<O&>().construct(std::declval<T*>(),
std::declval<Args&&>()...))>;
template<class>
static char check(long);
public:
BOOST_STATIC_CONSTEXPR bool value = sizeof(check<A>(0)) > 1;
};
#endif
template<bool, class = void>
struct alloc_if { };
template<class T>
struct alloc_if<true, T> {
typedef T type;
};
} /* detail */
#if defined(BOOST_NO_CXX11_ALLOCATOR)
template<class A, class T>
inline void
inline typename detail::alloc_if<detail::alloc_has_construct<A,
T>::value>::type
allocator_construct(A& a, T* p)
{
a.construct(p);
}
template<class A, class T>
inline typename detail::alloc_if<!detail::alloc_has_construct<A,
T>::value>::type
allocator_construct(A&, T* p)
{
::new((void*)p) T();
@ -467,24 +530,6 @@ allocator_construct(A&, T* p, V& v)
}
#endif
#else
namespace detail {
template<class A, class T, class... Args>
class alloc_has_construct {
template<class O>
static auto check(int)
-> alloc_no<decltype(std::declval<O&>().construct(std::declval<T*>(),
std::declval<Args&&>()...))>;
template<class>
static char check(long);
public:
BOOST_STATIC_CONSTEXPR bool value = sizeof(check<A>(0)) > 1;
};
} /* detail */
template<class A, class T, class... Args>
inline typename std::enable_if<detail::alloc_has_construct<A, T,
Args...>::value>::type
@ -502,17 +547,30 @@ allocator_construct(A&, T* p, Args&&... args)
}
#endif
#if defined(BOOST_NO_CXX11_ALLOCATOR)
template<class A, class T>
inline void
allocator_destroy(A&, T* p)
{
p->~T();
(void)p;
}
#else
namespace detail {
#if defined(BOOST_NO_CXX11_ALLOCATOR)
template<class A, class T>
class alloc_has_destroy {
template<class O>
static alloc_no<void(O::*)(T*), &O::destroy>
check(int);
template<class O>
static alloc_no<void(O::*)(T*) const, &O::destroy>
check(int);
template<class O>
static alloc_no<void(*)(T*), &O::destroy>
check(int);
template<class>
static char check(long);
public:
static const bool value = sizeof(check<A>(0)) > 1;
};
#else
template<class A, class T>
class alloc_has_destroy {
template<class O>
@ -525,33 +583,28 @@ class alloc_has_destroy {
public:
BOOST_STATIC_CONSTEXPR bool value = sizeof(check<A>(0)) > 1;
};
#endif
} /* detail */
template<class A, class T>
inline typename std::enable_if<detail::alloc_has_destroy<A, T>::value>::type
inline typename detail::alloc_if<detail::alloc_has_destroy<A, T>::value>::type
allocator_destroy(A& a, T* p)
{
a.destroy(p);
}
template<class A, class T>
inline typename std::enable_if<!detail::alloc_has_destroy<A, T>::value>::type
inline typename detail::alloc_if<!detail::alloc_has_destroy<A, T>::value>::type
allocator_destroy(A&, T* p)
{
p->~T();
(void)p;
}
#endif
namespace detail {
#if defined(BOOST_NO_CXX11_ALLOCATOR)
template<class T, T>
struct alloc_no {
char x, y;
};
template<class A>
class alloc_has_max_size {
template<class O>
@ -587,14 +640,6 @@ public:
};
#endif
template<bool, class>
struct alloc_if { };
template<class T>
struct alloc_if<true, T> {
typedef T type;
};
} /* detail */
template<class A>

16
test/allocator_construct_test.cpp
View File

@ -26,6 +26,16 @@ struct A2 {
};
#endif
template<class T>
struct A3 {
typedef T value_type;
A3() { }
template<class U>
void construct(U* p) {
::new((void*)p) U(1);
}
};
int main()
{
{
@ -42,5 +52,11 @@ int main()
BOOST_TEST_EQ(i, 6);
}
#endif
{
A3<int> a;
int i = 0;
boost::allocator_construct(a, &i);
BOOST_TEST_EQ(i, 1);
}
return boost::report_errors();
}

4
test/allocator_destroy_test.cpp
View File

@ -29,7 +29,6 @@ struct A1 {
A1() { }
};
#if !defined(BOOST_NO_CXX11_ALLOCATOR)
template<class T>
struct A2 {
typedef T value_type;
@ -39,7 +38,6 @@ struct A2 {
*p = U();
}
};
#endif
int main()
{
@ -50,13 +48,11 @@ int main()
BOOST_TEST_EQ(S::count, 0);
::new((void*)&s) S();
}
#if !defined(BOOST_NO_CXX11_ALLOCATOR)
{
A2<int> a;
int i = 5;
boost::allocator_destroy(a, &i);
BOOST_TEST_EQ(i, 0);
}
#endif
return boost::report_errors();
}