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Can `const char *` cause problems?

Can it be used free

for const char*

? Will this cause problems?

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No. By its very nature, one free()

needs the freedom to write into a given memory, to do "accounting". This is why he determined to take the pointer not const

.



As others have pointed out, this does not mean that it cannot work; C can drop the const

-ness of the pointer and let the function behave as if it were called without const

. The compiler will warn you when this happens, so I believe this is "causing problems".

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If the pointer is assigned yes. You will get a warning, but you have it when you highlighted it.

I use it a lot const char *

in my frameworks when I want to make sure no one else writes to them between distribution and release. It often happens that you dynamically create a string that is immutable for life, and if you call it with a function with side effects ( strtok

), you might run into problems. By declaring it const

, you can at least get a warning in this case.



const char *msg;

asprintf((char *)&msg, "whatever" ...);
...
strtok(msg, ",");     // Will generate a warning 
...
free((char*)msg);
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