[Bug c++/99076] New: Unclear error message when trailing angle bracket is missing

["bugzilla@poradnik-webmastera.com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99076

            Bug ID: 99076
           Summary: Unclear error message when trailing angle bracket is
                    missing
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bugzilla@poradnik-webmastera.com
  Target Milestone: ---

[code]
#include <memory>
#include <map>

template<
    typename Key,
    typename T,
    typename Compare = std::less<Key>,
    typename Allocator = std::allocator<std::pair<const Key, T>> >
using SecureMemMap = std::map<Key, T, Compare, std::allocator<std::pair<const
Key, T>>;
[/code]

When this is compiled using g++, it gives following error message:

[out]
<source>:9:53: error: template argument 4 is invalid
    9 | using SecureMemMap = std::map<Key, T, Compare,
std::allocator<std::pair<const Key, T>>;
      | 
[/out]

Above message is not very helpful, it is hard to tell what is wrong here.
clang++ does better job here. Please improve g++ message in a similar way:

[out]
<source>:9:87: error: expected '>'
using SecureMemMap = std::map<Key, T, Compare, std::allocator<std::pair<const
Key, T>>;
                                                                               
      ^
<source>:9:30: note: to match this '<'
using SecureMemMap = std::map<Key, T, Compare, std::allocator<std::pair<const
Key, T>>;
                             ^
[/out]