[Bug c++/83242] New: Never executed "throw" in constexpr function fails to compile

["benni.buch at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83242

            Bug ID: 83242
           Summary: Never executed "throw" in constexpr function fails to
                    compile
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: benni.buch at gmail dot com
  Target Milestone: ---

constexpr int f(){
    if(true) return 0;
    throw 0;
}

int main(){
    constexpr auto i = f();
}


Probably related to Bug 67371


$ g++ -std=c++14 main.cpp                                                       
main.cpp: In function 'constexpr int f()':
main.cpp:3:11: error: expression '<throw-expression>' is not a constant
expression
     throw 0;
           ^
main.cpp: In function 'int main()':
main.cpp:7:25: error: 'constexpr int f()' called in a constant expression
     constexpr auto i = f();
                        ~^~

$ g++ --version
g++ (GCC) 8.0.0 20171201 (experimental)
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This is free software; see the source for copying conditions.  There is NO
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