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std::shared_ptr::operatorbool(3) | C++ Standard Libary | std::shared_ptr::operatorbool(3) |
NAME¶
std::shared_ptr::operatorbool - std::shared_ptr::operatorbool
Synopsis¶
explicit operator bool() const noexcept;
Checks if *this stores a non-null pointer, i.e. whether get() != nullptr.
Parameters¶
(none)
Return value¶
true if *this stores a pointer, false otherwise.
Notes¶
An empty shared_ptr (where use_count() == 0) may store a non-null
pointer accessible
by get(), e.g. if it were created using the aliasing constructor.
Example¶
// Run this code
#include <iostream>
#include <memory>
void report(std::shared_ptr<int> ptr)
{
if (ptr)
std::cout << "*ptr=" << *ptr << "\n";
else
std::cout << "ptr is not a valid pointer.\n";
}
int main()
{
std::shared_ptr<int> ptr;
report(ptr);
ptr = std::make_shared<int>(7);
report(ptr);
}
Output:¶
ptr is not a valid pointer.
*ptr=7
See also¶
get returns the stored pointer
(public member function)
2024.06.10 | http://cppreference.com |