macro_rules! define_dbglike {
(
$( #[$meta:meta] )*
$name:ident,
$macro:path,
expect,
$format:literal,
$($args:tt)*
) => { ... };
(
$( #[$meta:meta] )*
$name:ident,
$macro:path,
try,
$format:literal,
$($args:tt)*
) => { ... };
}Expand description
Defines a dbg-like macro with a given name that uses
specified write macro, error-handling policy, format string and writer.
The implementation of the generated dbg-like macro
is based on std::dbg macro implementation,
but the exact output printed by std::dbg
should not be relied upon and is subject to future changes.
If the try policy is used, it propagates write error and
returns values wrapper into Result.
The writer itself is specified by the rest arguments with the define_writer macros.
ยงExamples
let mut string = String::new();
custom_print::define_dbglike!(cdbg, writeln, expect, ":?", fmt, |value: &str| string += value);
custom_print::define_dbglike!(try_dbg, writeln, try, ":?", fmt, |value: &str| string += value);
assert_eq!(cdbg!("first"), "first");
assert!(string.contains("\"first\""));
assert_eq!(try_dbg!("second"), Ok("second"));
assert!(string.contains("\"second\""));