/GF (Eliminate Duplicate Strings)
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/GF (Eliminate Duplicate Strings)

Enables the compiler to create a single copy of identical strings in the program image and in memory during execution, resulting in smaller programs, an optimization called string pooling.


/GF pools strings as read-only.

If you use /GF, the operating system does not swap the string portion of memory and can read the strings back from the image file. If you try to modify strings under /GF, an application error occurs.

String pooling allows what were intended as multiple pointers to multiple buffers to be as multiple pointers to a single buffer. In the following code, s and t are initialized with the same string. String pooling causes them to point to the same memory:

char *s = "This is a character buffer";
char *t = "This is a character buffer";

The/Z7, /Zi, /ZI (Debug Information Format) option, used for Edit and Continue, automatically sets the /GF option.

/GF is in effect when/O1, /O2 (Minimize Size, Maximize Speed) or /O2 is used.

To set this compiler option in the Visual Studio development environment

  1. Open the project's Property Pages dialog box. For details, see How to: Open Project Property Pages.

  2. Click the C/C++ folder.

  3. Click the Code Generation property page.

  4. Modify the Enable String Pooling property.

To set this compiler option programmatically

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