std::shared_ptr::operator bool
From cppreference.com
< cpp | memory | shared ptr
| explicit operator bool() const;
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Checks if *this stores a non-null pointer, i.e. whether get() != nullptr.
Contents |
[edit] Parameters
(none)
[edit] Return value
true if *this stores a pointer, false otherwise.
[edit] Exceptions
noexcept specification:
noexcept
[edit] 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.
[edit] Example
Run this code
#include <iostream> #include <memory> typedef std::shared_ptr<int> IntPtr; void report(IntPtr ptr) { if (ptr) { std::cout << "*ptr=" << *ptr << "\n"; } else { std::cout << "ptr is not a valid pointer.\n"; } } int main() { IntPtr ptr; report(ptr); ptr = IntPtr(new int(7)); report(ptr); }
Output:
ptr is not a valid pointer. *ptr=7
[edit] See also
| returns the stored pointer (public member function) |