/GR (Enable Run-Time Type Information)

Adds code to check object types at run time.

Syntax

/GR[-]

Remarks

When /GR is on, the compiler defines the _CPPRTTI preprocessor macro. By default, /GR is on. /GR- disables run-time type information.

Use /GR if the compiler cannot statically resolve an object type in your code. You usually need the /GR option when your code uses dynamic_cast Operator or typeid. However, /GR increases the size of the .rdata sections of your image. If your code does not use dynamic_cast or typeid, /GR- may produce a smaller image.

For more information about run-time type checking, see Run-Time Type Information in the C++ Language Reference.

To set this compiler option in the Visual Studio development environment

1. Open the project's Property Pages dialog box. For details, see Set C++ compiler and build properties in Visual Studio.

2. Select the Configuration Properties > C/C++ > Language property page.

3. Modify the Enable Run-Time Type Info property.

To set this compiler option programmatically

• See RuntimeTypeInfo.

See also

MSVC Compiler Options
MSVC Compiler Command-Line Syntax