diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/docs.rs | 1 | ||||
| -rw-r--r-- | src/docs/uninlined_format_args.txt | 36 |
2 files changed, 37 insertions, 0 deletions
diff --git a/src/docs.rs b/src/docs.rs index 6c89b4dde37..a501b56ffbe 100644 --- a/src/docs.rs +++ b/src/docs.rs @@ -521,6 +521,7 @@ docs! { "unimplemented", "uninit_assumed_init", "uninit_vec", + "uninlined_format_args", "unit_arg", "unit_cmp", "unit_hash", diff --git a/src/docs/uninlined_format_args.txt b/src/docs/uninlined_format_args.txt new file mode 100644 index 00000000000..3d2966c84db --- /dev/null +++ b/src/docs/uninlined_format_args.txt @@ -0,0 +1,36 @@ +### What it does +Detect when a variable is not inlined in a format string, +and suggests to inline it. + +### Why is this bad? +Non-inlined code is slightly more difficult to read and understand, +as it requires arguments to be matched against the format string. +The inlined syntax, where allowed, is simpler. + +### Example +``` +format!("{}", var); +format!("{v:?}", v = var); +format!("{0} {0}", var); +format!("{0:1$}", var, width); +format!("{:.*}", prec, var); +``` +Use instead: +``` +format!("{var}"); +format!("{var:?}"); +format!("{var} {var}"); +format!("{var:width$}"); +format!("{var:.prec$}"); +``` + +### Known Problems + +There may be a false positive if the format string is expanded from certain proc macros: + +``` +println!(indoc!("{}"), var); +``` + +If a format string contains a numbered argument that cannot be inlined +nothing will be suggested, e.g. `println!("{0}={1}", var, 1+2)`. \ No newline at end of file |