1.10.0[][src]Struct std::panic::Location

#[lang = "panic_location"]pub struct Location<'a> { /* fields omitted */ }

A struct containing information about the location of a panic.

This structure is created by the location method of PanicInfo.

Examples

This example panics
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");
Run

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.

Implementations

impl<'a> Location<'a>[src]

pub fn caller() -> &'static Location<'static>1.46.0[src]

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 core::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());
Run

impl<'a> Location<'a>[src]

pub fn file(&self) -> &str[src]

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

This example panics
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");
Run

pub fn line(&self) -> u32[src]

Returns the line number from which the panic originated.

Examples

This example panics
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");
Run

pub fn column(&self) -> u321.25.0[src]

Returns the column from which the panic originated.

Examples

This example panics
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");
Run

Trait Implementations

impl<'a> Clone for Location<'a>[src]

impl<'a> Copy for Location<'a>[src]

impl<'a> Debug for Location<'a>[src]

impl<'_> Display for Location<'_>1.26.0[src]

impl<'a> Eq for Location<'a>[src]

impl<'a> Hash for Location<'a>[src]

impl<'a> Ord for Location<'a>[src]

impl<'a> PartialEq<Location<'a>> for Location<'a>[src]

impl<'a> PartialOrd<Location<'a>> for Location<'a>[src]

impl<'a> StructuralEq for Location<'a>[src]

impl<'a> StructuralPartialEq for Location<'a>[src]

Auto Trait Implementations

impl<'a> RefUnwindSafe for Location<'a>

impl<'a> Send for Location<'a>

impl<'a> Sync for Location<'a>

impl<'a> Unpin for Location<'a>

impl<'a> UnwindSafe for Location<'a>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> ToOwned for T where
    T: Clone
[src]

type Owned = T

The resulting type after obtaining ownership.

impl<T> ToString for T where
    T: Display + ?Sized
[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.