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The header <boost/core/demangle.hpp>
defines several tools for undecorating symbol names.
namespace boost { namespace core { std::string demangle( char const * name ); char const * demangle_alloc( char const * name ) noexcept; void demangle_free( char const * demangled_name ) noexcept; class scoped_demangled_name { public: explicit scoped_demangled_name( char const * name ) noexcept; ~scoped_demangled_name() noexcept; char const * get() const noexcept; scoped_demangled_name( scoped_demangled_name const& ) = delete; scoped_demangled_name& operator= ( scoped_demangled_name const& ) = delete; }; } }
The function boost::core::demangle is the conventional way to obtain
demangled symbol name. It takes a mangled string such as those returned
by typeid(T).name() on certain implementations such as g++,
and returns its demangled, human-readable, form. In case if demangling
fails (e.g. if name cannot
be interpreted as a mangled name) the function returns name.
#include <boost/core/demangle.hpp> #include <typeinfo> #include <iostream> template<class T> struct X { }; int main() { char const * name = typeid( X<int> ).name(); std::cout << name << std::endl; // prints 1XIiE std::cout << boost::core::demangle( name ) << std::endl; // prints X<int> }
In some cases more low level interface may be desirable. For example:
The function boost::core::demangle_alloc performs name demangling
and returns a pointer to a string with the demangled name, if succeeded,
or nullptr otherwise. The
returned pointer must be passed to boost::core::demangle_free
to reclaim resources. Note that on some platforms the pointer returned
by boost::core::demangle_alloc may refer to the string
denoted by name, so this
string must be kept immutable for the whole life time of the returned pointer.
The boost::core::scoped_demangled_name class is a scope
guard that automates the calls to boost::core::demangle_alloc
(on its construction) and boost::core::demangle_free
(on destruction). The string with the demangled name can be obtained with
its get method. Note that
this method may return nullptr
if demangling failed.
#include <boost/core/demangle.hpp> #include <typeinfo> #include <iostream> template<class T> struct X { }; int main() { char const * name = typeid( X<int> ).name(); boost::core::scoped_demangled_name demangled( name ); std::cout << name << std::endl; // prints 1XIiE std::cout << (demangled.get() ? demangled.get() : "[unknown]") << std::endl; // prints X<int> }
The implementation of core::demangle
was taken from boost/exception/detail/type_info.hpp, which in turn was adapted from boost/units/detail/utility.hpp and boost/log/utility/type_info_wrapper.hpp.