How to deal with noexcept in Visual Studio

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一整个雨季
一整个雨季 2021-01-31 07:42

I\'m trying to create a custom exception that derives from std::exception and overrides what(). At first, I wrote it like this:

class U         


        
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  • 2021-01-31 08:16

    The other way to go around is create header file and include it if necessary in your source code that should be compile by gcc, vc,or clang.

    no_except_work_around.h

    #ifndef no_except_work_around_H
    #define no_except_work_around_H
    
    #if (_MSC_VER <= 1800)
    #include <xkeycheck.h>
    #define noexcept
    #endif 
    
    #endif //no_except_work_around_H
    

    =====================================================

    P.S> doesn't cover case noexcept(false) but works fine for VC2010,2012,2013, gcc 4.9

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  • 2021-01-31 08:17

    #IFs may work, even if a bit hacky.

    You could just do this:

    #if __GNUG__
    virtual const char* what() const noexcept override
    #else
    virtual const char* what() const override
    #endif
    //method body
    
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  • 2021-01-31 08:20

    This check works to see if noexcept is supported:

    // Is noexcept supported?
    #if defined(__clang__) && __has_feature(cxx_noexcept) || \
        defined(__GXX_EXPERIMENTAL_CXX0X__) && __GNUC__ * 10 + __GNUC_MINOR__ >= 46 || \
        defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 180021114
    #  define NOEXCEPT noexcept
    #else
    #  define NOEXCEPT
    #endif
    

    The above works with Clang, GCC and MSVC.

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  • 2021-01-31 08:20

    use BOOST_NOEXCEPT in <boost/config.hpp>

    The boost config library was designed for compatibility issues like this. According to the doc:

    If BOOST_NO_CXX11_NOEXCEPT is defined (i.e. C++03 compliant compilers) these macros are defined as:

        #define BOOST_NOEXCEPT
        #define BOOST_NOEXCEPT_OR_NOTHROW throw()
        #define BOOST_NOEXCEPT_IF(Predicate)
        #define BOOST_NOEXCEPT_EXPR(Expression) false
    

    If BOOST_NO_CXX11_NOEXCEPT is not defined (i.e. C++11 compliant compilers) they are defined as:

        #define BOOST_NOEXCEPT noexcept
        #define BOOST_NOEXCEPT_OR_NOTHROW noexcept
        #define BOOST_NOEXCEPT_IF(Predicate) noexcept((Predicate))
        #define BOOST_NOEXCEPT_EXPR(Expression) noexcept((Expression))
    

    Many of the other answers here have a similar implementation but this library is cleaner, better tested, and will do the right thing when your compiler is upgraded. I recommend looking at the boost config library in general for other features, especially in this time of language flux and varying levels of support among compilers.

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  • 2021-01-31 08:21

    "noexcept" is only supported since the Visual Studio 2015 (as stated here: https://msdn.microsoft.com/en-us/library/wfa0edys.aspx). I have used following code with Visual Studio 2013 (derived from above examples):

    #if !defined(HAS_NOEXCEPT)
    #if defined(__clang__)
    #if __has_feature(cxx_noexcept)
    #define HAS_NOEXCEPT
    #endif
    #else
    #if defined(__GXX_EXPERIMENTAL_CXX0X__) && __GNUC__ * 10 + __GNUC_MINOR__ >= 46 || \
        defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 190023026
    #define HAS_NOEXCEPT
    #endif
    #endif
    
    #ifdef HAS_NOEXCEPT
    #define NOEXCEPT noexcept
    #else
    #define NOEXCEPT
    #endif
    
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  • 2021-01-31 08:23

    Use a macro

    #ifndef _MSC_VER
    #define NOEXCEPT noexcept
    #else
    #define NOEXCEPT
    #endif
    

    And then define the function as

    virtual const char* what() const NOEXCEPT override
    

    You could also modify that to allow noexcept on later versions of VS by checking the value of _MSC_VER; for VS2012 the value is 1600.

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