[expr.call]/1 Lacking `defnx` for "function call"

[BlowingWind314]

[expr.call]/1 seems to be the only place defining what is a "function call":

A function call is a postfix expression followed by parentheses containing a possibly empty, comma-separated list of initializer-clauses which constitute the arguments to the function.

The Index already includes "recursive function call" and "undefined function call". Lacking for the "function call" itself reveals imcompleteness.

[eisenwave]

I think we have a number of these expressions where we refer to them as "subscript expression" or whatever without having a formal definition, and it's just some ancient pre-existing quirk where everyone knows what we mean.

The key question is whether we are committed to the term "call" or want to phase it out in favor of "invocation" over time, in which case it doesn't make much sense to polish this area of wording.

[BlowingWind314]

I think we have a number of these expressions where we refer to them as "subscript expression" or whatever without having a formal definition, and it's just some ancient pre-existing quirk where everyone knows what we mean.

Well actually subscript expression is defined. Comparing with something like "postfix ++ expression" (also lacking a definition), I think the "function call" is of its own significance.

The key question is whether we are committed to the term "call" or want to phase it out in favor of "invocation" over time, in which case it doesn't make much sense to polish this area of wording.

Whether the word is replaced or not, the "function call/invocation expression" itself deserves a definition. BTW, I suppose currently "call" refers to the expression and "invocation" refers to its evaluation, which is elegant in my point of view.

[BlowingWind314]

See also P4176.

[jensmaurer]

The strategy here would be to use "function call" for things that use function call syntax (i.e. f(something) ) and use "invocation of a function" for any transfer of control to a function, regardless of how it is accomplished (that includes implicit destructor calls, calls to conversion operators, calls to default constructors, etc.) [expr.call] isn't stellar in differentiating this.