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Mar 12, 2010 · free(p); instructs the memory management logic (of the C Runtime) that the memory previously occupied by the block which p points to can be reused. p = NULL; sets the …
May 28, 2017 · In the bad old days of C (back around 1986, on a pre-ANSI standard cc compiler) free (NULL) would dump core. So most devs tested for NULL/0 before calling free.
Sep 11, 2022 · The free function causes the space pointed to by ptr to be deallocated, that is, made available for further allocation. If ptr is a null pointer, no action occurs.
Nov 19, 2015 · You cannot free const char * because it is const. Store pointers received from malloc in non-const pointer variables, so that you can pass them to free. You can pass char * …
Apr 3, 2011 · 15 free releases the memory at that address. It doesn't change the p variable itself. However, doing anything with p after that point is undefined behavior. It may seem to work if …
Jun 6, 2016 · This, plus of course many times p is only going to be a local stack variable anyway in which case having set it to NULL becomes irrelevant as soon as it goes out of scope. Also, if …
Jul 25, 2011 · The other is the delete expression, delete p;, where p is a T*. The expression invokes the destructor of the object pointed to by p (and then frees the memory), which is a …
Dec 18, 2012 · 23 p holds a copy of a (presumably valid) address, so free (p) tries to, well, free it. But since it is a copy, it cannot really free it. It's not true. free() can work just fine if p is a valid …
Allegedly, setting a pointer to NULL after free is supposed to prevent the dreaded 'double free' problem when the same pointer value is passed to free more than once. In reality though, in 9 …
Jan 2, 2017 · Yes -- free takes a pointer to void, so when you call it, the pointer is (implicitly) cast to a pointer to void in any case. The rest of your code isn't quite so safe: void* p = …
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