Function operator== (proxy<F>)
friend bool operator==(const proxy& lhs, std::nullptr_t) noexcept;
Checks whether lhs contains a value by comparing it with nullptr. A proxy that does not contain a value compares equal to nullptr; otherwise, it compares non-equal.
This function is not visible to ordinary unqualified or qualified lookup. It can only be found by argument-dependent lookup when proxy<F> is an associated class of the arguments.
The != operator is synthesized from operator==.
Return Value
!lhs.has_value().
Example
#include <iostream>
#include <proxy/proxy.h>
struct AnyMovable : pro::facade_builder::build {};
int main() {
pro::proxy<AnyMovable> p;
std::cout << std::boolalpha << (p == nullptr) << "\n"; // Prints "true"
std::cout << (p != nullptr) << "\n"; // Prints "false"
p = std::make_unique<int>(123);
std::cout << (p == nullptr) << "\n"; // Prints "false"
std::cout << (p != nullptr) << "\n"; // Prints "true"
}