printf! behaving inconsistently with a single argument

[bluss]

With a single argument, printf! goes back to just rendering the %? representation of a value, even if it's a string.

compare these two invocations and their output:

printf!("test\n")
"test\n"

printf!("%s\n", "test")
test

[alexcrichton]

The cause for this is that fmt!(a) == fmt!("%?", a) (at least that's what it's transformed to). The %? representation makes the string printing weird.

Now that we have a generic printf macro though I agree that this should definitely be addressed.

[catamorphism]

Visiting for triage. Unfortunate, but not a milestone blocker.

[alexcrichton]

Closing due to being old, printf has been removed and print does not have this behavior.