[Bug c++/88512] New: Too much STL in error output

[jg at jguk dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88512

            Bug ID: 88512
           Summary: Too much STL in error output
           Product: gcc
           Version: 8.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jg at jguk dot org
  Target Milestone: ---

Hello

Could the STL template output be reduced? It currently is roughly double that
of CLANG. Although I think can reasonably get down to 3 lines. Output included
below, and an example of something more brief.


// g++ -Wall -o stl_string stl_string.cpp
#include <string>
int main()
{
    std::string str("hello ");
    std::size_t s = str.find(" ");
    str.erase(s, str.end());
}

Expected output something similar to the following expected

stl_string.cpp: In function ‘int main()’:
stl_string.cpp:10:15: error: invalid conversion from ‘std::size_t’
’const_iterator’  std::string erase()


Actual output:
$ g++ -Wall -o stl_string stl_string.cpp
stl_string.cpp: In function ‘int main()’:
stl_string.cpp:7:27: error: no matching function for call to
‘std::__cxx11::basic_string<char>::erase(std::size_t&,
std::__cxx11::basic_string<char>::iterator)’
     str.erase(s, str.end());
                           ^
In file included from /usr/include/c++/7/string:52:0,
                 from stl_string.cpp:2:
/usr/include/c++/7/bits/basic_string.h:1779:7: note: candidate:
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&
std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::erase(std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type,
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type) [with _CharT =
char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>;
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::size_type = long unsigned
int]
       erase(size_type __pos = 0, size_type __n = npos)
       ^~~~~
/usr/include/c++/7/bits/basic_string.h:1779:7: note:   no known conversion for
argument 2 from ‘std::__cxx11::basic_string<char>::iterator {aka
__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >}’ to
‘std::__cxx11::basic_string<char>::size_type {aka long unsigned int}’
/usr/include/c++/7/bits/basic_string.h:1798:7: note: candidate:
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator
std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::erase(std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::__const_iterator) [with _CharT = char; _Traits =
std::char_traits<char>; _Alloc = std::allocator<char>;
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator =
__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >;
typename __gnu_cxx::__alloc_traits<typename
__gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::pointer = char*;
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__const_iterator =
__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >;
typename __gnu_cxx::__alloc_traits<typename
__gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::const_pointer =
const char*]
       erase(__const_iterator __position)
       ^~~~~
/usr/include/c++/7/bits/basic_string.h:1798:7: note:   candidate expects 1
argument, 2 provided
/usr/include/c++/7/bits/basic_string.h:1817:7: note: candidate:
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator
std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::erase(std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::__const_iterator, std::__cxx11::basic_string<_CharT, _Traits,
_Alloc>::__const_iterator) [with _CharT = char; _Traits =
std::char_traits<char>; _Alloc = std::allocator<char>;
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::iterator =
__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >;
typename __gnu_cxx::__alloc_traits<typename
__gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::pointer = char*;
std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::__const_iterator =
__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >;
typename __gnu_cxx::__alloc_traits<typename
__gnu_cxx::__alloc_traits<_Alloc>::rebind<_CharT>::other>::const_pointer =
const char*]
       erase(__const_iterator __first, __const_iterator __last)
       ^~~~~
/usr/include/c++/7/bits/basic_string.h:1817:7: note:   no known conversion for
argument 1 from ‘std::size_t {aka long unsigned int}’ to
‘std::__cxx11::basic_string<char>::__const_iterator {aka
__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >}’



CLANG:
$ clang -Wall -o stl_string stl_string.cpp
stl_string.cpp:7:9: error: no matching member function for call to 'erase'
    str.erase(s, str.end());
    ~~~~^~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/basic_string.h:1789:7:
note: candidate
      function not viable: no known conversion from
'std::__cxx11::basic_string<char, std::char_traits<char>,
      std::allocator<char> >::iterator' (aka '__normal_iterator<char *,
std::__cxx11::basic_string<char> >') to
      'std::__cxx11::basic_string<char, std::char_traits<char>,
std::allocator<char> >::size_type'
      (aka 'unsigned long') for 2nd argument
      erase(size_type __pos = 0, size_type __n = npos)
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/basic_string.h:1827:7:
note: candidate
      function not viable: no known conversion from 'std::size_t' (aka
'unsigned long') to
      'std::__cxx11::basic_string<char, std::char_traits<char>,
std::allocator<char> >::__const_iterator' (aka
      '__normal_iterator<const char *, std::__cxx11::basic_string<char> >') for
1st argument
      erase(__const_iterator __first, __const_iterator __last)
      ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/basic_string.h:1808:7:
note: candidate
      function not viable: requires single argument '__position', but 2
arguments were provided
      erase(__const_iterator __position)
      ^
1 error generated.