rust/library/core/tests/fmt/mod.rs
T-O-R-U-S 72a25d05bf Use implicit capture syntax in format_args
This updates the standard library's documentation to use the new syntax. The
documentation is worthwhile to update as it should be more idiomatic
(particularly for features like this, which are nice for users to get acquainted
with). The general codebase is likely more hassle than benefit to update: it'll
hurt git blame, and generally updates can be done by folks updating the code if
(and when) that makes things more readable with the new format.

A few places in the compiler and library code are updated (mostly just due to
already having been done when this commit was first authored).
2022-03-10 10:23:40 -05:00

46 lines
1.3 KiB
Rust

mod builders;
mod float;
mod num;
#[test]
fn test_format_flags() {
// No residual flags left by pointer formatting
let p = "".as_ptr();
assert_eq!(format!("{:p} {:x}", p, 16), format!("{p:p} 10"));
assert_eq!(format!("{: >3}", 'a'), " a");
}
#[test]
fn test_pointer_formats_data_pointer() {
let b: &[u8] = b"";
let s: &str = "";
assert_eq!(format!("{s:p}"), format!("{:p}", s.as_ptr()));
assert_eq!(format!("{b:p}"), format!("{:p}", b.as_ptr()));
}
#[test]
fn test_estimated_capacity() {
assert_eq!(format_args!("").estimated_capacity(), 0);
assert_eq!(format_args!("{}", "").estimated_capacity(), 0);
assert_eq!(format_args!("Hello").estimated_capacity(), 5);
assert_eq!(format_args!("Hello, {}!", "").estimated_capacity(), 16);
assert_eq!(format_args!("{}, hello!", "World").estimated_capacity(), 0);
assert_eq!(format_args!("{}. 16-bytes piece", "World").estimated_capacity(), 32);
}
#[test]
fn pad_integral_resets() {
struct Bar;
impl core::fmt::Display for Bar {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
"1".fmt(f)?;
f.pad_integral(true, "", "5")?;
"1".fmt(f)
}
}
assert_eq!(format!("{Bar:<03}"), "1 0051 ");
}