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Support C++03 implementations that require reference and const_pointer

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This commit is contained in:
Glen Fernandes
2019-04-27 02:31:09 -04:00
parent 5a549b8b22
commit 151f2cf645
3 changed files with 95 additions and 3 deletions
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8
doc/default_allocator.qbk
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@ -21,9 +21,8 @@ The header <boost/core/default_allocator.hpp> provides the class template
* Like C++2a's `std::allocator`, does not provide members such as `construct()`
and `destroy()` to be eligible for optimizations by allocator-aware code that
detects the absence of these members to provide more optimal construction of
objects.
* Supports `BOOST_NO_EXCEPTIONS`.
detects the absence of these members to provide more optimal construction.
* Supports `BOOST_NO_EXCEPTIONS` in allocation.
* Does not have `std` as an associated namespace.
[endsect]
@ -37,6 +36,9 @@ template<class T>
struct default_allocator {
typedef T value_type;
typedef T* pointer;
typedef const T* const_pointer;
typedef std::add_lvalue_reference_t<T> reference;
typedef std::add_lvalue_reference_t<const T> const_reference;
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
typedef ``['true_type]`` propagate_on_container_move_assignment;

36
include/boost/core/default_allocator.hpp
View File

@ -12,6 +12,12 @@ Distributed under the Boost Software License, Version 1.0.
#include <new>
#include <climits>
#if defined(BOOST_NO_CXX11_ALLOCATOR)
#define BOOST_CORE_NO_CXX11_ALLOCATOR
#elif defined(BOOST_LIBSTDCXX_VERSION) && BOOST_LIBSTDCXX_VERSION < 60000
#define BOOST_CORE_NO_CXX11_ALLOCATOR
#endif
namespace boost {
#if defined(BOOST_NO_EXCEPTIONS)
@ -35,10 +41,28 @@ struct true_type {
}
};
template<class T>
struct add_reference {
typedef T& type;
};
template<>
struct add_reference<void> {
typedef void type;
};
template<>
struct add_reference<const void> {
typedef const void type;
};
template<class T>
struct default_allocator {
typedef T value_type;
typedef T* pointer;
typedef const T* const_pointer;
typedef typename add_reference<T>::type reference;
typedef typename add_reference<const T>::type const_reference;
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
typedef true_type propagate_on_container_move_assignment;
@ -97,6 +121,18 @@ struct default_allocator {
::operator delete(p, std::nothrow);
}
#endif
#if defined(BOOST_CORE_NO_CXX11_ALLOCATOR)
template<class U, class V>
void construct(U* p, const V& v) {
::new(p) U(v);
}
template<class U>
void destroy(U* p) {
p->~U();
}
#endif
};
template<class T, class U>

54
test/default_allocator_test.cpp
View File

@ -7,6 +7,8 @@ Distributed under the Boost Software License, Version 1.0.
*/
#include <boost/core/default_allocator.hpp>
#include <boost/core/lightweight_test_trait.hpp>
#include <vector>
#include <list>
class type {
public:
@ -44,6 +46,42 @@ void test_pointer()
boost::default_allocator<void>::pointer);
}
void test_const_pointer()
{
BOOST_TEST_TRAIT_SAME(const int*,
boost::default_allocator<int>::const_pointer);
BOOST_TEST_TRAIT_SAME(const type*,
boost::default_allocator<type>::const_pointer);
BOOST_TEST_TRAIT_SAME(const int(*)[5],
boost::default_allocator<int[5]>::const_pointer);
BOOST_TEST_TRAIT_SAME(const void*,
boost::default_allocator<void>::const_pointer);
}
void test_reference()
{
BOOST_TEST_TRAIT_SAME(int&,
boost::default_allocator<int>::reference);
BOOST_TEST_TRAIT_SAME(type&,
boost::default_allocator<type>::reference);
BOOST_TEST_TRAIT_SAME(int(&)[5],
boost::default_allocator<int[5]>::reference);
BOOST_TEST_TRAIT_SAME(void,
boost::default_allocator<void>::reference);
}
void test_const_reference()
{
BOOST_TEST_TRAIT_SAME(const int&,
boost::default_allocator<int>::const_reference);
BOOST_TEST_TRAIT_SAME(const type&,
boost::default_allocator<type>::const_reference);
BOOST_TEST_TRAIT_SAME(const int(&)[5],
boost::default_allocator<int[5]>::const_reference);
BOOST_TEST_TRAIT_SAME(const void,
boost::default_allocator<void>::const_reference);
}
void test_size_type()
{
BOOST_TEST_TRAIT_SAME(std::size_t,
@ -203,10 +241,25 @@ void test_not_equals()
boost::default_allocator<int>()));
}
void test_container()
{
std::vector<int, boost::default_allocator<int> > v;
v.push_back(1);
BOOST_TEST(v.size() == 1);
BOOST_TEST(v.front() == 1);
std::list<int, boost::default_allocator<int> > l;
l.push_back(1);
BOOST_TEST(l.size() == 1);
BOOST_TEST(l.front() == 1);
}
int main()
{
test_value_type();
test_pointer();
test_const_pointer();
test_reference();
test_const_reference();
test_size_type();
test_difference_type();
test_propagate_on_container_move_assignment();
@ -219,5 +272,6 @@ int main()
test_allocate_deallocate();
test_equals();
test_not_equals();
test_container();
return boost::report_errors();
}