ceph/src/boost/libs/type_index/examples/demangled_names.cpp

   1 // Copyright 2013-2019 Antony Polukhin
   2
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See the accompanying file LICENSE_1_0.txt
   5 // or a copy at <http://www.boost.org/LICENSE_1_0.txt>.)
   6
   7
   8 //[type_index_names_example
   9 /*`
  10     The following example shows how short (mangled) and human readable type names could be obtained from a type.
  11     Works with and without RTTI.
  12 */
  13
  14
  15 #include <boost/type_index.hpp>
  16 #include <iostream>
  17
  18 template <class T>
  19 void foo(T) {
  20     std::cout << "\n Short name: " << boost::typeindex::type_id<T>().raw_name();
  21     std::cout << "\n Readable name: " << boost::typeindex::type_id<T>().pretty_name();
  22 }
  23
  24 struct user_defined_type{};
  25
  26 namespace ns1 { namespace ns2 {
  27     struct user_defined_type{};
  28 }} // namespace ns1::ns2
  29
  30 namespace {
  31     struct in_anon_type{};
  32 } // anonymous namespace
  33
  34 int main() {
  35     // Call to
  36     foo(1);
  37     // will output something like this:
  38     //
  39     // (RTTI on)                                            (RTTI off)
  40     // Short name: i                                        Short name: int]
  41     // Readable name: int                                   Readable name: int
  42
  43     user_defined_type t;
  44     foo(t);
  45     // Will output:
  46     //
  47     // (RTTI on)                                            (RTTI off)
  48     // Short name: 17user_defined_type                      user_defined_type]
  49     // Readable name: user_defined_type                     user_defined_type
  50
  51     ns1::ns2::user_defined_type t_in_ns;
  52     foo(t_in_ns);
  53     // Will output:
  54     //
  55     // (RTTI on)                                            (RTTI off)
  56     // Short name: N3ns13ns217user_defined_typeE            ns1::ns2::user_defined_type]
  57     // Readable name: ns1::ns2::user_defined_type           ns1::ns2::user_defined_type
  58
  59     in_anon_type anon_t;
  60     foo(anon_t);
  61     // Will output:
  62     //
  63     // (RTTI on)                                            (RTTI off)
  64     // Short name: N12_GLOBAL__N_112in_anon_typeE           {anonymous}::in_anon_type]
  65     // Readable name: (anonymous namespace)::in_anon_type   {anonymous}::in_anon_type
  66 }
  67
  68 /*`
  69     Short names are very compiler dependant: some compiler will output `.H`, others `i`.
  70
  71     Readable names may also differ between compilers: `struct user_defined_type`, `user_defined_type`.
  72
  73     [warning With RTTI off different classes with same names in anonymous namespace may collapse. See 'RTTI emulation limitations'. ]
  74 */
  75
  76 //] [/type_index_names_example]