Compiler Warning (level 4) C4431
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Compiler Warning (level 4) C4431

Error Message

missing type specifier - int assumed. Note: C no longer supports default-int

This error can be generated as a result of compiler conformance work that was done for Visual C++ 2005: Visual C++ no longer creates untyped identifiers as int by default. The type of an identifier must be specified explicitly. See Breaking Changes in the Visual C++ 2005 Compiler for more information.

This warning is off by default. See Compiler Warnings That Are Off by Default for more information.


The following sample generates C4431.

// C4431.c
// compile with: /c /W4
#pragma warning(default:4431)
i;   // C4431
int i;   // OK
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