std::str: Remove functions count_chars, count_bytes #8857
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These are very easy to replace with methods on string slices, basically
`.char_len()` and `.len()`.
These are the replacement implementations I did to clean these
functions up, but seeing this I propose removal:
/// ...
pub fn count_chars(s: &str, begin: uint, end: uint) -> uint {
// .slice() checks the char boundaries
s.slice(begin, end).char_len()
}
/// Counts the number of bytes taken by the first `n` chars in `s`
/// starting from byte index `begin`.
///
/// Fails if there are less than `n` chars past `begin`
pub fn count_bytes<'b>(s: &'b str, begin: uint, n: uint) -> uint {
s.slice_from(begin).slice_chars(0, n).len()
}
bors
added a commit
that referenced
this pull request
Aug 30, 2013
These are very easy to replace with methods on string slices, basically
`.char_len()` and `.len()`.
These are the replacement implementations I did to clean these
functions up, but seeing this I propose removal:
/// ...
pub fn count_chars(s: &str, begin: uint, end: uint) -> uint {
// .slice() checks the char boundaries
s.slice(begin, end).char_len()
}
/// Counts the number of bytes taken by the first `n` chars in `s`
/// starting from byte index `begin`.
///
/// Fails if there are less than `n` chars past `begin`
pub fn count_bytes<'b>(s: &'b str, begin: uint, n: uint) -> uint {
s.slice_from(begin).slice_chars(0, n).len()
}
Jarcho
pushed a commit
to Jarcho/rust
that referenced
this pull request
Aug 29, 2022
Add test for rust-lang#8855 Fix rust-lang#8855 Here is what I think is going on. First, the expression `format!("{:>6} {:>6}", a, b.to_string())` expands to: ```rust { let res = ::alloc::fmt::format(::core::fmt::Arguments::new_v1_formatted(&["", " "], &[::core::fmt::ArgumentV1::new_display(&a), ::core::fmt::ArgumentV1::new_display(&b.to_string())], &[::core::fmt::rt::v1::Argument { position: 0usize, format: ::core::fmt::rt::v1::FormatSpec { fill: ' ', align: ::core::fmt::rt::v1::Alignment::Right, flags: 0u32, precision: ::core::fmt::rt::v1::Count::Implied, width: ::core::fmt::rt::v1::Count::Is(6usize), }, }, ::core::fmt::rt::v1::Argument { position: 1usize, format: ::core::fmt::rt::v1::FormatSpec { fill: ' ', align: ::core::fmt::rt::v1::Alignment::Right, flags: 0u32, precision: ::core::fmt::rt::v1::Count::Implied, width: ::core::fmt::rt::v1::Count::Is(6usize), }, }], unsafe { ::core::fmt::UnsafeArg::new() })); res } ``` When I dump the expressions that get past the call to `has_string_formatting` [here](https://github.com/rust-lang/rust-clippy/blob/b312ad7d0cf0f30be2bd4658b71a3520a2e76709/clippy_lints/src/format_args.rs#L83), I see more than I would expect. In particular, I see this subexpression of the above: ``` &[::core::fmt::ArgumentV1::new_display(&a), ::core::fmt::ArgumentV1::new_display(&b.to_string())], ``` This suggests to me that more expressions are getting past [this call](https://github.com/rust-lang/rust-clippy/blob/b312ad7d0cf0f30be2bd4658b71a3520a2e76709/clippy_lints/src/format_args.rs#L71) to `FormatArgsExpn::parse` than should. Those expressions are then visited, but no `::core::fmt::rt::v1::Argument`s are found and pushed [here](https://github.com/rust-lang/rust-clippy/blob/b312ad7d0cf0f30be2bd4658b71a3520a2e76709/clippy_utils/src/macros.rs#L407). As a result, the expressions appear unformatted, hence, the false positive. My proposed fix is to restrict `FormatArgsExpn::parse` so that it only matches `Call` expressions. cc: `@akanalytics` changelog: none
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These are very easy to replace with methods on string slices, basically
.char_len()and.len().These are the replacement implementations I did to clean these
functions up, but seeing this I propose removal:
/// ...
pub fn count_chars(s: &str, begin: uint, end: uint) -> uint {
// .slice() checks the char boundaries
s.slice(begin, end).char_len()
}
/// Counts the number of bytes taken by the first
nchars ins/// starting from byte index
begin.///
/// Fails if there are less than
nchars pastbeginpub fn count_bytes<'b>(s: &'b str, begin: uint, n: uint) -> uint {
s.slice_from(begin).slice_chars(0, n).len()
}