blob: b6e298084e4542fe6dcc1aa978fdea64bc2e0d43 [file] [log] [blame]
#include <memory>
namespace android {
namespace pdx {
namespace rpc {
// Allocator adaptor that interposes construct() calls to convert value
// initialization into default initialization. All standard containers
// value-initialize their elements when constructed with a single size_type
// argument or when grown by a call to resize. This allocator avoids potentially
// costly value-initialization in these situations for value types that are
// default constructible. As a consequence, elements of non-class types are left
// uninitialized; this is desirable when using std::vector as a resizable
// buffer, for example.
template <typename T, typename Allocator = std::allocator<T>>
class DefaultInitializationAllocator : public Allocator {
typedef std::allocator_traits<Allocator> AllocatorTraits;
template <typename U>
struct rebind {
using other = DefaultInitializationAllocator<
U, typename AllocatorTraits::template rebind_alloc<U>>;
using Allocator::Allocator;
template <typename U>
void construct(U* pointer) noexcept(
std::is_nothrow_default_constructible<U>::value) {
::new (static_cast<void*>(pointer)) U;
template <typename U, typename... Args>
void construct(U* pointer, Args&&... args) {
AllocatorTraits::construct(static_cast<Allocator&>(*this), pointer,
} // namespace rpc
} // namespace pdx
} // namespace android