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Diffstat (limited to 'src/macros.rs')
| -rw-r--r-- | src/macros.rs | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/macros.rs b/src/macros.rs index 558a4a9..55977a4 100644 --- a/src/macros.rs +++ b/src/macros.rs @@ -31,3 +31,36 @@ macro_rules! time { (result, dt) }}; } + +/// Conditionally perform string formatting. +/// +/// If `$enabled` is true, then do the formatting and return a `Cow::Owned`. +/// +/// Otherwise, just return the borrowed (often `'static`) string +/// `$borrowed`. +/// +/// When `$enabled` is false, this avoids the overhead of allocating +/// and writing to a buffer, as well as any overhead or side effects +/// of the format arguments. +#[macro_export] +macro_rules! format_if { + ($enabled:expr, $borrowed:expr, $fmt:expr, $($args:expr),*) => { + if $enabled { + ::std::borrow::Cow::Owned(format!($fmt, $($args),*)) as ::std::borrow::Cow<str> + } else { + ::std::borrow::Cow::Borrowed($borrowed) + } + } +} + +/// Generate a test function `$name` which asserts that `$left` and `$right` +/// are equal. +#[macro_export] +macro_rules! test_eq { + ($name:ident, $left:expr, $right:expr) => { + #[test] + fn $name() { + assert_eq!($left, $right); + } + } +}
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