Boost
boost
arrow_drop_down
Boost news learn community libraries releases
PrevUpHomeNext

Chapter 40. Boost.TypeIndex 4.1

Copyright © 2012-2024 Antony Polukhin

Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

Table of Contents

Motivation
Getting started
How to use
Example with Boost.Any
Example with Boost.Variant
Configuring and building the library
How it works
Examples
Getting human readable and mangled type names
Storing information about a type in container
Getting through the inheritance to receive a real type name
Using runtime_cast where RTTI is unavailable or undesirable
Exact type matching: storing type with const, volatile and reference qualifiers
Table of raw_name() and pretty_name() outputs with and without RTTI
C++14: Checking namespace at compile time
C++14: Checking lexigraphical order of provided types
Boost.TypeIndex Header Reference
Header <boost/type_index.hpp>
Header <boost/type_index/ctti_type_index.hpp>
Header <boost/type_index/runtime_cast.hpp>
Header <boost/type_index/runtime_cast/boost_shared_ptr_cast.hpp>
Header <boost/type_index/runtime_cast/pointer_cast.hpp>
Header <boost/type_index/runtime_cast/reference_cast.hpp>
Header <boost/type_index/runtime_cast/register_runtime_class.hpp>
Header <boost/type_index/runtime_cast/std_shared_ptr_cast.hpp>
Header <boost/type_index/stl_type_index.hpp>
Header <boost/type_index/type_index_facade.hpp>
Making a custom type_index
Basics
Getting type infos at runtime
Using new type infos all around the code
Space and Performance
Code bloat
RTTI emulation limitations
Define the BOOST_TYPE_INDEX_FUNCTION_SIGNATURE macro
Fixing pretty_name() output
Mixing sources with RTTI on and RTTI off
Acknowledgements

Sometimes getting and storing information about a type at runtime is required. For such cases a construction like &typeid(T) or C++11 class std::type_index is usually used, which is where problems start:

  • typeid(T) and std::type_index require Run Time Type Info (RTTI)
  • some implementations of typeid(T) erroneously do not strip const, volatile and references from type
  • some compilers have bugs and do not correctly compare std::type_info objects across shared libraries
  • only a few implementations of Standard Library currently provide std::type_index
  • no easy way to store type info without stripping const, volatile and references
  • no nice and portable way to get human readable type names
  • no way to easily make your own type info class

Boost.TypeIndex library was designed to work around all those issues.

[Note] Note

T means type here. Think of it as of T in template <class T>

PrevUpHomeNext