gcc/testsuite/g++.dg/concepts/diagnostic5.C: In function ‘void bar()’:         
gcc/testsuite/g++.dg/concepts/diagnostic5.C:42:13: error: use of function ‘void foo() [with T = char]’ with unsatisfied constraints
   42 |   foo<char>(); // { dg-error "use of" }                                                                                    
      |             ^                                                                                                              
gcc/testsuite/g++.dg/concepts/diagnostic5.C:37:8: note: declared here                                                              
   37 |   void foo() { }                                                                                                           
      |        ^~~                                                                                                                 
gcc/testsuite/g++.dg/concepts/diagnostic5.C:37:8: note: constraints not satisfied                                                  
gcc/testsuite/g++.dg/concepts/diagnostic5.C: In instantiation of ‘void foo() [with T = char]’:                                     
gcc/testsuite/g++.dg/concepts/diagnostic5.C:42:13:   required from here                                                            
gcc/testsuite/g++.dg/concepts/diagnostic5.C:37:8:   required by the constraints of ‘template<class T>  requires (c1<T>) || (c2<T>) || ((c3<T>) || (c4<T>)) || (c5<T>) void foo()’
gcc/testsuite/g++.dg/concepts/diagnostic5.C:31:49: note: no operand of the disjunction is satisfied                                                                              
   31 |   requires (c1<T> || c2<T>) || (c3<T> || c4<T>) || c5<T> // { dg-message "49: no operand" }                                                                              
      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~                                                                                                                 
cc1plus: note: set -fconcepts-diagnostics-depth= to at least 2 for more detail