Precompiled Headers & Normal C++ Semantics
By Jeffrey Taylor, October 01, 2001
If arranged correctly, precompiled headers, like those in Visual C++, can double the build speed. However, it is possible also to arrange precompiled header files in a manner that is inconsistent with normal C++ semantics.
Oct01: Precompiled Headers & Normal C++ Semantics
<b>(a)</b> pch.h
// Sun Forte C++: The contents of this file will be
// included through normal C++ semantics.
// MS Visual C++: The contents of this file will be
// included through the precompiled header.
#include <iostream.h>
#define STR1 "James "
#define STR2 "Brown"
<b>(b)</b> pch.cpp
// Do add anything to this file!
// Any additional code should be placed in pch.h.
#include "pch.h"
<b>(c)</b> main.cpp
#include "pch.h"
int main()
{
cout << STR1;
cout << STR2;
return 0;
}
Example 2: This C++ program has the same behavior on NT and UNIX: (a) pch.h; (b) pch.cpp; (c) main.cpp.
