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In file corelib/global/qglobal.cpp of QtCore
What is difference between
Version one
void *qMalloc(size_t size) { return ::malloc(size); }
1950 void qFree(void *ptr) { ::free(ptr); }
1951 void *qRealloc(void *ptr, size_t size) { return ::realloc(ptr, size); }Version 2
Void* qMalloc(size_t sz) {return malloc(sz);}
void qFree(void* ptr) {free(ptr);}
void* qRealloc(void* ptr, size_t sz) {return realloc(ptr, sz);}Are they same
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Hi,
The double column operator is called the scope-resolution operator. When used like that it will resolve the malloc symbol starting at the global namespace.
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Did not get that will that if you could explain more by example
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:: = scope-resolution operator. The name.
void someclass::func() {
cow(); // this looks in someclass for cow() and then global
}void someclass::func() {
::cow(); // this looks in global first, then in class to find cow()
}so its a way of saying, Im talking about the global one or please look for a global version first.
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but as I understand we do have nor definition our own malloc defined this the following will be same
Version one
void *qMalloc(size_t size) { return ::malloc(size); }
1950 void qFree(void *ptr) { ::free(ptr); }
1951 void *qRealloc(void *ptr, size_t size) { return ::realloc(ptr, size); }Version 2
Void* qMalloc(size_t sz) {return malloc(sz);}
void qFree(void* ptr) {free(ptr);}
void* qRealloc(void* ptr, size_t sz) {return realloc(ptr, sz);} -
@Qt-Enthusiast This is done to make sure that the global one is used. Even if you don't have any other at the moment, later someone could add one. To make sure that the global one is always used you write ::malloc
You should ask C++ related questions here: https://forum.qt.io/category/34/c-gurus
This is a C++ question not related to Qt.
