On Saturday, 17 March 2018 at 10:34:41 UTC, dom wrote:
Hi,
I am looking for a method to log the current function name +
parameters.
Getting the name of the current function is simply possible
with __PRETTY_FUNCTION__
Is there some possibility to generically access the parameters
of a function such that they can be iterated and printed out?
currently i have something like this:
log.info(__PRETTY_FUNCTION__, " ", parameter1, " ",
parameter2);
i would like to get to something like that:
log.info(__PRETTY_FUNCTION__, " ", parameters.join(", "));
You may be able to do something with a mixin. I tried this but I
think I'm hitting a compiler bug, or I'm just using mixins wrong.
import std.stdio;
string arguments(alias f)() {
import std.meta: AliasSeq;
import std.traits: ParameterIdentifierTuple;
import std.array: join;
string[] args;
foreach (a; [AliasSeq!(ParameterIdentifierTuple!f)]) {
args ~= `"` ~ a ~ `: ", ` ~ a;
}
return args.join(`, ", ", `);
}
// calling writeln(mixin(arguments!f)) should do what you want.
void f(int a, int b, int c) {
// But you get a:
// Error: Using the result of a comma expression is not
allowed
// writeln(mixin(arguments!f));
auto value = arguments!f; // "a: ", a, ", ", "b: ", b, ", ",
"c: ", c
writeln(value);
// This is ok:
writeln("a: ", a, ", ", "b: ", b, ", ", "c: ", c);
}
void main() {
f(1, 2, 3);
}
You might be able to start with that and get something that
works. Or maybe someone knows how to make the mixin part above
compile. I have a feeling you may need to make the arguments()
function return a string("p0: ", arg0, ", p1: ", arg1" ...)
instead so that it's a full string instead of a comma separated
expression maybe.
Cheers
