Location in core::panic - Rust (original) (raw)
Struct Location
1.41.0 · Source
pub struct Location<'a> { /* private fields */ }Expand description
A struct containing information about the location of a panic.
This structure is created by PanicHookInfo::location() and PanicInfo::location().
§Examples
use std::panic;
panic::set_hook(Box::new(|panic_info| {
if let Some(location) = panic_info.location() {
println!("panic occurred in file '{}' at line {}", location.file(), location.line());
} else {
println!("panic occurred but can't get location information...");
}
}));
panic!("Normal panic");§Comparisons
Comparisons for equality and ordering are made in file, line, then column priority. Files are compared as strings, not Path, which could be unexpected. See Location::file’s documentation for more discussion.
1.46.0 (const: 1.79.0) · Source
Returns the source location of the caller of this function. If that function’s caller is annotated then its call location will be returned, and so on up the stack to the first call within a non-tracked function body.
§Examples
use std::panic::Location;
/// Returns the [`Location`] at which it is called.
#[track_caller]
fn get_caller_location() -> &'static Location<'static> {
Location::caller()
}
/// Returns a [`Location`] from within this function's definition.
fn get_just_one_location() -> &'static Location<'static> {
get_caller_location()
}
let fixed_location = get_just_one_location();
assert_eq!(fixed_location.file(), file!());
assert_eq!(fixed_location.line(), 14);
assert_eq!(fixed_location.column(), 5);
// running the same untracked function in a different location gives us the same result
let second_fixed_location = get_just_one_location();
assert_eq!(fixed_location.file(), second_fixed_location.file());
assert_eq!(fixed_location.line(), second_fixed_location.line());
assert_eq!(fixed_location.column(), second_fixed_location.column());
let this_location = get_caller_location();
assert_eq!(this_location.file(), file!());
assert_eq!(this_location.line(), 28);
assert_eq!(this_location.column(), 21);
// running the tracked function in a different location produces a different value
let another_location = get_caller_location();
assert_eq!(this_location.file(), another_location.file());
assert_ne!(this_location.line(), another_location.line());
assert_ne!(this_location.column(), another_location.column());1.10.0 (const: 1.79.0) · Source
Returns the name of the source file from which the panic originated.
§&str, not &Path
The returned name refers to a source path on the compiling system, but it isn’t valid to represent this directly as a &Path. The compiled code may run on a different system with a different Path implementation than the system providing the contents and this library does not currently have a different “host path” type.
The most surprising behavior occurs when “the same” file is reachable via multiple paths in the module system (usually using the #[path = "..."] attribute or similar), which can cause what appears to be identical code to return differing values from this function.
§Cross-compilation
This value is not suitable for passing to Path::new or similar constructors when the host platform and target platform differ.
§Examples
use std::panic;
panic::set_hook(Box::new(|panic_info| {
if let Some(location) = panic_info.location() {
println!("panic occurred in file '{}'", location.file());
} else {
println!("panic occurred but can't get location information...");
}
}));
panic!("Normal panic");1.10.0 (const: 1.79.0) · Source
Returns the line number from which the panic originated.
§Examples
use std::panic;
panic::set_hook(Box::new(|panic_info| {
if let Some(location) = panic_info.location() {
println!("panic occurred at line {}", location.line());
} else {
println!("panic occurred but can't get location information...");
}
}));
panic!("Normal panic");1.25.0 (const: 1.79.0) · Source
Returns the column from which the panic originated.
§Examples
use std::panic;
panic::set_hook(Box::new(|panic_info| {
if let Some(location) = panic_info.location() {
println!("panic occurred at column {}", location.column());
} else {
println!("panic occurred but can't get location information...");
}
}));
panic!("Normal panic");Tests for self and other values to be equal, and is used by ==.
Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
This method returns an ordering between self and other values if one exists. Read more
Tests less than (for self and other) and is used by the < operator. Read more
Tests less than or equal to (for self and other) and is used by the<= operator. Read more
Tests greater than (for self and other) and is used by the >operator. Read more
Tests greater than or equal to (for self and other) and is used by the >= operator. Read more