Trait WelpResultExt 

pub trait WelpResultExt<T, E>: Sized {
    // Required methods
    fn welp(self) -> Result<T, Welp>;
    fn welp_context(self, message: impl Into<String>) -> Result<T, Welp>;
    fn with_welp_context<S, F>(self, f: F) -> Result<T, Welp>
       where S: Into<String>,
             F: FnOnce(&E) -> S;
}

Extension trait on Result for attaching a string message that produces a Welp.

Bring this into scope via use oopsie::prelude::* (or use oopsie_core::WelpResultExt).

use oopsie_core::{Welp, WelpResultExt as _};

fn read(path: &str) -> Result<String, Welp> {
    std::fs::read_to_string(path).welp_context("could not read")
}

Required Methods

fn welp(self) -> Result<T, Welp>

Convert the error into a Welp with no user message — the kind of message-free ?-style conversion anyhow/eyre give you for free. The resulting Welp’s Display delegates to the source’s, and the source stays reachable through Error::source. Reach for welp_context instead when a string adds information the source doesn’t already carry.

fn welp_context(self, message: impl Into<String>) -> Result<T, Welp>

Wrap the error in a Welp with the given message.

Note: the message argument is evaluated at the call site per Rust’s eager-argument rules — welp_context(format!(...)) allocates the formatted String even on the Ok branch. Use with_welp_context when the message is built from a non-trivial expression that should only run on Err.

fn with_welp_context<S, F>(self, f: F) -> Result<T, Welp>

where S: Into<String>, F: FnOnce(&E) -> S,

Wrap the error in a Welp with a lazily-built message. The closure runs only on the Err branch and receives a shared reference to the source error.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl<T, E> WelpResultExt<T, E> for Result<T, E>

where E: StdError + Send + Sync + 'static,

fn welp(self) -> Result<T, Welp>

fn welp_context(self, message: impl Into<String>) -> Result<T, Welp>

fn with_welp_context<S, F>(self, f: F) -> Result<T, Welp>

where S: Into<String>, F: FnOnce(&E) -> S,

Implementors