detect-mismatch.md

description	title	ms.date	f1_keywords	helpviewer_keywords	no-loc
Learn more about the detect_mismatch pragma directive in Microsoft C/C++	detect_mismatch pragma	01/22/2021	vc-pragma.detect_mismatch detect_mismatch_CPP	pragma, detect_mismatch detect_mismatch pragma	pragma

detect_mismatch pragma

Places a record in an object. The linker checks these records for potential mismatches.

Syntax

#pragma detect_mismatch( "name" , "value" )

Remarks

When you link the project, the linker throws a LNK2038 error if the project contains two objects that have the same name but each has a different value. Use this pragma to prevent inconsistent object files from linking.

Both name and value are string literals and obey the rules for string literals with respect to escape characters and concatenation. They are case-sensitive and cannot contain a comma, equal sign, quotation marks, or the null character.

Example

This example creates two files that have different version numbers for the same version label.

// pragma_directive_detect_mismatch_a.cpp
#pragma detect_mismatch("myLib_version", "9")
int main ()
{
   return 0;
}

// pragma_directive_detect_mismatch_b.cpp
#pragma detect_mismatch("myLib_version", "1")

If you compile both of these files by using the command line cl pragma_directive_detect_mismatch_a.cpp pragma_directive_detect_mismatch_b.cpp, you will receive the error LNK2038.

See also

Pragma directives and the __pragma and _Pragma keywords