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boost/core/demangle.hpp

作用

我們都知道，C++中，編譯變數，類，及全域性函式，編譯後的名稱，已經發生了改變，我們稱之為 新增修飾。那麼，我們有什麼方法將這種修飾，擦除掉呢？，demangle能夠幫助我們完成這一項功能。

舉例

boost::core::demangled_name

#include <boost/core/typeinfo.hpp>
#include <iostream>

template<class T1, class T2> struct Y1
{
};

int main()
{
    typedef Y1<int, long> T;
    std::cout << boost::core::demangled_name( BOOST_CORE_TYPEID( T ) );

	char ch;
	std::cin>>ch;

    return 0;
}
 

執行結果

boost::core::demangle

#include <boost/core/demangle.hpp>
#include <typeinfo>
#include <iostream>

template<class T1, class T2> struct Y1
{
};

void test_demangle()
{
    typedef Y1<int, long> T;
    std::cout << boost::core::demangle( typeid( T ).name() ) << std::endl;
}

int main()
{
    test_demangle();
    char ch;
    std::cin>>ch;

    return 0;
}
 

執行結果

boost::core::demangle_alloc及boost::core::demangle_free

#include <boost/core/demangle.hpp>
#include <typeinfo>
#include <iostream>

template<class T1, class T2> struct Y1
{
};

void test_demangle_alloc()
{
    typedef Y1<int, long> T;
    const char* p = boost::core::demangle_alloc( typeid( T ).name() );
    if (p)
    {
        std::cout << p << std::endl;
        boost::core::demangle_free(p);
    }
    else
    {
        std::cout << "[demangling failed]" << std::endl;
    }
}

int main()
{
    test_demangle_alloc();
    
    char ch;
    std::cin>>ch;

    return 0;
}
 

執行結果

boost::core::scoped_demangled_name demangled_name

#include <boost/core/demangle.hpp>
#include <typeinfo>
#include <iostream>

template<class T1, class T2> struct Y1
{
};

void test_scoped_demangled_name()
{
    typedef Y1<int, long> T;
    boost::core::scoped_demangled_name demangled_name( typeid( T ).name() );
    const char* p = demangled_name.get();
    if (p)
    {
        std::cout << p << std::endl;
    }
    else
    {
        std::cout << "[demangling failed]" << std::endl;
    }
}

int main()
{
    test_scoped_demangled_name();

    char ch;
    std::cin>>ch;

    return 0;
}

執行結果

原始碼

namespace boost
{

namespace core
{

inline char const * demangle_alloc( char const * name ) BOOST_NOEXCEPT;
inline void demangle_free( char const * name ) BOOST_NOEXCEPT;

class scoped_demangled_name
{
private:
    char const * m_p;

public:
    explicit scoped_demangled_name( char const * name ) BOOST_NOEXCEPT :
        m_p( demangle_alloc( name ) )
    {
    }

    ~scoped_demangled_name() BOOST_NOEXCEPT
    {
        demangle_free( m_p );
    }

    char const * get() const BOOST_NOEXCEPT
    {
        return m_p;
    }

    BOOST_DELETED_FUNCTION(scoped_demangled_name( scoped_demangled_name const& ))
    BOOST_DELETED_FUNCTION(scoped_demangled_name& operator= ( scoped_demangled_name const& ))
};


#if defined( BOOST_CORE_HAS_CXXABI_H )

inline char const * demangle_alloc( char const * name ) BOOST_NOEXCEPT
{
    int status = 0;
    std::size_t size = 0;
    return abi::__cxa_demangle( name, NULL, &size, &status );
}

inline void demangle_free( char const * name ) BOOST_NOEXCEPT
{
    std::free( const_cast< char* >( name ) );
}

inline std::string demangle( char const * name )
{
    scoped_demangled_name demangled_name( name );
    char const * p = demangled_name.get();
    if( !p )
        p = name;
    return p;
}

#else

inline char const * demangle_alloc( char const * name ) BOOST_NOEXCEPT
{
    return name;
}

inline void demangle_free( char const * ) BOOST_NOEXCEPT
{
}

inline std::string demangle( char const * name )
{
    return name;
}

#endif

} // namespace core

} // namespace boost