TestForSSTREAM — CMake 4.3.0 Documentation

# TestForSSTREAM

This module checks whether the C++ standard header `<sstream>` exists and functions correctly.

Load this module in a CMake project with:

    include(TestForSSTREAM)

In early versions of C++ (pre-C++98), the `<sstream>` header was not formally standardized and may not have been available.

This module defines the following cache variables:

`CMAKE_NO_ANSI_STRING_STREAM`

  A cache variable indicating whether the `<sstream>` header is available. It will be set to value `0` if `<sstream>` is available (`C++ 98` and newer), and to value `1` if `<sstream>` is missing (`ANSI C++`).

`CMAKE_HAS_ANSI_STRING_STREAM`

  A cache variable that is the opposite of `CMAKE_NO_ANSI_STRING_STREAM` (true if `<sstream>` is available and false if `<sstream>` is missing).

Note

The `<sstream>` header was formally introduced in the `C++ 98` standard, making this check obsolete for modern compilers.

## Examples

Including this module will check for `<sstream>` support and define the `CMAKE_NO_ANSI_STRING_STREAM` cache variable:

`CMakeLists.txt`

    include(TestForSSTREAM)
    file(
      CONFIGURE
      OUTPUT config.h
      CONTENT "#cmakedefine CMAKE_NO_ANSI_STRING_STREAM"
    )

Then it can be used in a C++ program:

`example.cxx`

    #include "config.h"

    #ifndef CMAKE_NO_ANSI_STRING_STREAM
    #  include <sstream>
    #endif

    int main() { ... }

## See Also

- The `CMakeBackwardCompatibilityCXX` module.