ignore_unused

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## ignore_unused

### Authors

- Adam Wulkiewicz

### Header <boost/core/ignore_unused.hpp>

The header `<boost/core/ignore_unused.hpp>` defines the function template `boost::ignore_unused()`. It may be used to suppress the "unused variable" or "unused local typedefs" compiler warnings when the variable or typedef can't be removed or commented out, e.g. when some blocks of the code are conditionally activated. C++11 variadic templates are used if they're supported, otherwise they're emulated with overloads.

#### Usage

    boost::ignore_unused(v1, v2, v3);
    boost::ignore_unused<T1, T2, T3>();

#### Example

    int fun( int foo, int bar )
    {
        boost::ignore_unused(bar);
    #ifdef ENABLE_DEBUG_OUTPUT
        if ( foo < bar )
            std::cerr << "warning! foo < bar";
    #endif
        return foo + 2;
    }

### Acknowledgments

`boost::ignore_unused()` was contributed by Adam Wulkiewicz.