std::shared_ptr<T>::operator bool
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< cpp | memory | shared ptr
C++
Utilities library
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Dynamic memory management
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std::shared_ptr
Member functions | ||||
Modifiers | ||||
Observers | ||||
(C++17) | ||||
(until C++20) | ||||
shared_ptr::operator bool | ||||
Non-member functions | ||||
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20) | ||||
functions (deprecated in C++20) | ||||
(C++20) | ||||
Deduction guides(C++17) |
explicit operator bool() const noexcept; |
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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
returns the stored pointer (public member function) |