Compiler Warning (Level 1) C4739
Visual Studio 2015
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at Compiler Warning (Level 1) C4739.
reference to variable 'var' exceeds its storage space
A value was assigned to a variable, but the value is greater than the size of the variable. Memory will be written beyond the variable's memory location, and data loss is possible.
To resolve this warning, only assign a value to a variable whose size can accommodate the value.
The following sample generates C4739:
// C4739.cpp
// compile with: /RTCs /Zi /W1 /c
char *pc;
int main() {
char c;
*(int *)&c = 1; // C4739
// OK
*(char *)&c = 1;
}
Show: