Toto je testovací kód, který se pochopitelně nezkompiluje, a i kdyby, nic
rozumného dělat nebude. Stejně jako strcpy se chová i free.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main (void)
{
const char * str1 = (char*) malloc(10*sizeof(char));
char * const str2 = (char*) malloc(10*sizeof(char));
const char * const str3 = (char*) malloc(10*sizeof(char));
str1 = NULL;
str2 = NULL;
str3 = NULL;
strcpy(str1, "a");
strcpy(str2, "a");
strcpy(str3, "a");
return 0;
}
Jak to vidí GCC 4.4.5
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x = NULL
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strcpy(x, “a”)
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const char *
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OK
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error: invalid conversion from ‘const char’ to ’char’
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char * const
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error: assignment to read-only variable
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OK
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const char * const
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error: assignment to read-only variable
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error: invalid conversion from ‘const char’ to ’char’
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Jak to vidí CLang 1.1
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x = NULL
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strcpy(x, “a”)
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const char *
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OK
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error: no matching function for call to 'strcpy'
note: candidate function not viable: 1st argument
('char const *const') would lose const qualifier
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char * const
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error: read-only variable is not assignable
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OK
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const char * const
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error: read-only variable is not assignable
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error: no matching function for call to 'strcpy'
note: candidate function not viable: 1st argument
('char const *const') would lose const qualifier
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