[SUGGESTION] `if (i==j)` gives clang warning about (i==j)

[realgdman]

if (i==j) in cpp2, when lowered to cpp1, encloses condition in parens if ((i==j))
Which is, probably, for good, but in modern C++, for example clang, gives a warning

https://cpp2.godbolt.org/z/av3ech559

warning: equality comparison with extraneous parentheses [-Wparentheses-equality]
note: remove extraneous parentheses around the comparison to silence this warning
note: use '=' to turn this equality comparison into an assignment

It can be a problem if "threat warnings as error" enabled, in case of mixed cpp1/cpp2.

[JohelEGP]

Redundant parentheses are used for this:

if (a = b) // Warning, `=` instead of `==`.
if ((a = b)) // Redundant `()`s convey intention to use `=` conventionally.

But if a = b and if (a = b) are not valid Cpp2,
so redundant parentheses needn't be lowered to a Cpp1 condition as-is.

[realgdman]

Hm, looks this cpp2 valid currently
https://cpp2.godbolt.org/z/bGPqKK3nc

b:= false;
c:= true;
if(b) 		{ foo(true); } else { foo(false); }
if(b=c) 	{ foo(true); } else { foo(false); }
if((b=c)) 	{ foo(true); } else { foo(false); }

i:= 0;
j:= 1;
if(i) 		{ foo(true); } else { foo(false); }
if(i=j) 	{ foo(true); } else { foo(false); }
if((i=j)) 	{ foo(true); } else { foo(false); }

prints 0,1,1,0,1,1

[JohelEGP]

You're right.
It's only if a = b that's rejected.
if (a = b) isn't.
Because the grammar is 'if' logical-or-expression.

So only if (a == b) don't need the redundant parentheses lowered to Cpp1 to avoid warnings.
Or maybe it's good that they're lowered to Cpp1 as-is,
because it means, "hey, you used redundant parentheses in Cpp2!"

[JohelEGP]

Or maybe it's good that they're lowered to Cpp1 as-is,
because it means, "hey, you used redundant parentheses in Cpp2!"

So this is a non-bug (much less a suggestion).

[realgdman]

I should be clearer, cppfront add extra parens. So if ((i==1)) becames if (((i==1))) etc

[JohelEGP]

It's not extra. It's the same you write.
if a is Cpp2, and has to lower to Cpp1 if (a).