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From: "tangyixuan at mail dot dlut.edu.cn" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/97420] New: error: no matching function for call to 'find_if'
Date: Wed, 14 Oct 2020 13:51:36 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97420

            Bug ID: 97420
           Summary: error: no matching function for call to 'find_if'
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tangyixuan at mail dot dlut.edu.cn
  Target Milestone: ---

Hi, the following code maybe valid, since 'std::find_if' is allowed since
c++17.
https://en.cppreference.com/w/cpp/algorithm/find

$ cat s.cpp

# include <cctype>
# include <algorithm>

template<int (& F)(int)>
constexpr int A(unsigned char a) noexcept(noexcept(F(a)))
{ return F(a); }

int main()
{
    const char t[] =3D "a";

    std::find_if(t, t + 1, A<std::isspace>);
}

$ g++ -c -std=3Dc++2a s.cpp
s.cpp: In function =E2=80=98int main()=E2=80=99:
s.cpp:12:43: error: no matching function for call to =E2=80=98find_if(const=
 char [2],
const char*, <unresolved overloaded function type>)=E2=80=99
   12 |     std::find_if(t, t + 1, A<std::isspace>);
      |=