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MuldeR's Utilities for Qt
MUtilities
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Lazy initialization template class. More...
#include <Lazy.h>
Public Member Functions | |
| Lazy (std::function< T *(void)> &&initializer) | |
| T & | operator* (void) |
| T * | operator-> (void) |
| bool | initialized () |
Protected Member Functions | |
| __forceinline T * | getValue () |
Lazy initialization template class.
The lazy-initialized value of type T can be obtained from a Lazy<T> instance by using the operator*(). Initialization of the value happens when the operator*() is called for the very first time, by invoking the initializer lambda-function that was passed to the constructor. The return value of the initializer lambda-function is then stored internally, so that any subsequent call to the operator*() immediately returns the previously created value.
Note on thread-saftey: This class is thread-safe in the sense that all calls to operator*() on the same Lazy<T> instance, regardless from which thread, are guaranteed to return the exactly same value/object. The first thread trying to access the value will invoke the initializer lambda-function; concurrent threads may need to busy-wait until the initialization is completed. The initializer lambda-function is invoked at most once.
1.8.12