message
Sends a string literal to the standard output without terminating the compilation.
#pragma message( messagestring )
Remarks
A typical use of the message pragma is to display informational messages at compile time.
The messagestring parameter can be a macro that expands to a string literal, and you can concatenate such macros with string literals in any combination.
If you use a predefined macro in the message pragma, the macro should return a string, else you will have to convert the output of the macro to a string.
The following code fragment uses the message pragma to display messages during compilation:
// pragma_directives_message1.cpp
// compile with: /LD
#if _M_IX86 >= 500
#pragma message("_M_IX86 >= 500")
#endif
#pragma message("")
#pragma message( "Compiling " __FILE__ )
#pragma message( "Last modified on " __TIMESTAMP__ )
#pragma message("")
// with line number
#define STRING2(x) #x
#define STRING(x) STRING2(x)
#pragma message (__FILE__ "[" STRING(__LINE__) "]: test")
#pragma message("")