https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113904
--- Comment #5 from sandra at gcc dot gnu.org --- Per TR12, these are the rules for the scoping/evaluation of these expressions: "For the match clause of a declare variant directive, any argument of the base function that is referenced in an expression that appears in the context selector is treated as a reference to the expression that is passed into that argument at the call to the base function. Otherwise, a variable or procedure reference in an expression that appears in a context selector is a reference to the variable or procedure of that name that is visible at the location of the directive on which the context selector appears." C: "Any expressions in the match clause are interpreted as if they appeared in the scope of arguments of the base function." C++: "any expressions in the match clause are interpreted as if they appeared at the scope of the trailing return type of the base function." Plus, confusingly, it also says: "All variables referenced by these expressions are considered to be referenced at the call site." "All variables that are referenced in an expression that appears in the context selector of a match clause must be accessible at each call site to the base function according to the base language rules." So maybe the intent is that the variables be parsed in the scope of the directive but then the expressions be inserted inline at the call site, rather than wrapping them with an internal function? :-S
