make_proxy_inplaceThe definition of make_proxy_inplace makes use of an exposition-only class template sbo-ptr. Similar to std::optional, sbo-ptr<T> contains the storage for an object of type T, manages its lifetime, and provides operator* for access with the same qualifiers. However, it does not necessarily support the state where the contained object is absent. sbo-ptr<T> has the same size and alignment as T.
// (1)
template <facade F, inplace_proxiable_target<F> T, class... Args>
proxy<F> make_proxy_inplace(Args&&... args)
noexcept(std::is_nothrow_constructible_v<T, Args...>);
// (2)
template <facade F, inplace_proxiable_target<F> T, class U, class... Args>
proxy<F> make_proxy_inplace(std::initializer_list<U> il, Args&&... args)
noexcept(std::is_nothrow_constructible_v<
T, std::initializer_list<U>&, Args...>);
// (3)
template <facade F, class T>
proxy<F> make_proxy_inplace(T&& value)
noexcept(std::is_nothrow_constructible_v<std::decay_t<T>, T>)
requires(inplace_proxiable_target<std::decay_t<T>, F>);
(1) Creates a proxy<F> object containing a value p of type sbo-ptr<T>, where *p is direct-non-list-initialized with std::forward<Args>(args)....
(2) Creates a proxy<F> object containing a value p of type sbo-ptr<T>, where *p is direct-non-list-initialized with il, std::forward<Args>(args)....
(3) Creates a proxy<F> object containing a value p of type sbo-ptr<std::decay_t<T>>, where *p is direct-non-list-initialized with std::forward<T>(value).
The constructed proxy object.
Throws any exception thrown by the constructor of T.
#include <array>
#include "proxy.h"
// By default, the maximum pointer size defined by pro::facade_builder
// is 2 * sizeof(void*). This value can be overridden by `restrict_layout`.
struct Any : pro::facade_builder::build {};
int main() {
// sizeof(int) is usually not greater than sizeof(void*) for modern
// 32/64-bit compilers
pro::proxy<Any> p1 = pro::make_proxy_inplace<Any>(123);
// sizeof(std::array<int, 100>) is usually greater than 2 * sizeof(void*)
// pro::proxy<Any> p2 = pro::make_proxy_inplace<Any, std::array<int, 100>>(); // Won't compile
}