Result alias for convienient use of anyhow::Error without depending on anyhow (#5853)

* Add a Result type alias

* Refer to the type in top-level docs

* Use this inside the documentation for the bindgen! macro

* Fix tests

* Address small PR feedback

* Simply re-export anyhow types

crates/wasmtime/src/component/mod.rs

@@ -82,7 +82,6 @@ pub(crate) use self::store::ComponentStoreData;
 /// Then you can interact with the generated bindings like so:
 ///
 /// ```rust,ignore
-/// use anyhow::Result;
 /// use wasmtime::component::*;
 /// use wasmtime::{Config, Engine, Store};
 ///
@@ -97,12 +96,12 @@ pub(crate) use self::store::ComponentStoreData;
 /// impl HelloWorldImports for MyState {
 ///     // Note the `Result` return value here where `Ok` is returned back to
 ///     // the component and `Err` will raise a trap.
-///     fn name(&mut self) -> Result<String> {
+///     fn name(&mut self) -> wasmtime::Result<String> {
 ///         Ok(self.name.clone())
 ///     }
 /// }
 ///
-/// fn main() -> Result<()> {
+/// fn main() -> wasmtime::Result<()> {
 ///     // Configure an `Engine` and compile the `Component` that is being run for
 ///     // the application.
 ///     let mut config = Config::new();
@@ -168,7 +167,6 @@ pub(crate) use self::store::ComponentStoreData;
 /// Then you can interact with the generated bindings like so:
 ///
 /// ```rust,ignore
-/// use anyhow::Result;
 /// use wasmtime::component::*;
 /// use wasmtime::{Config, Engine, Store};
 ///
@@ -180,16 +178,16 @@ pub(crate) use self::store::ComponentStoreData;
 ///
 /// // Note that the trait here is per-interface and within a submodule now.
 /// impl host::Host for MyState {
-///     fn gen_random_integer(&mut self) -> Result<u32> {
+///     fn gen_random_integer(&mut self) -> wasmtime::Result<u32> {
 ///         Ok(rand::thread_rng().gen())
 ///     }
 ///
-///     fn sha256(&mut self, bytes: Vec<u8>) -> Result<String> {
+///     fn sha256(&mut self, bytes: Vec<u8>) -> wasmtime::Result<String> {
 ///         // ...
 ///     }
 /// }
 ///
-/// fn main() -> Result<()> {
+/// fn main() -> wasmtime::Result<()> {
 ///     let mut config = Config::new();
 ///     config.wasm_component_model(true);
 ///     let engine = Engine::new(&config)?;

crates/wasmtime/src/lib.rs

@@ -27,10 +27,9 @@
 //! An example of using Wasmtime looks like:
 //!
 //! ```
-//! use anyhow::Result;
 //! use wasmtime::*;
 //!
-//! fn main() -> Result<()> {
+//! fn main() -> wasmtime::Result<()> {
 //!     // Modules can be compiled through either the text or binary format
 //!     let engine = Engine::default();
 //!     let wat = r#"
@@ -141,10 +140,9 @@
 //! For example we can reimplement the above example with a `Linker`:
 //!
 //! ```
-//! use anyhow::Result;
 //! use wasmtime::*;
 //!
-//! fn main() -> Result<()> {
+//! fn main() -> wasmtime::Result<()> {
 //!     let engine = Engine::default();
 //!     let wat = r#"
 //!         (module
@@ -301,11 +299,10 @@
 //! An example of using WASI looks like:
 //!
 //! ```no_run
-//! # use anyhow::Result;
 //! # use wasmtime::*;
 //! use wasmtime_wasi::sync::WasiCtxBuilder;
 //!
-//! # fn main() -> Result<()> {
+//! # fn main() -> wasmtime::Result<()> {
 //! // Compile our module and create a `Linker` which has WASI functions defined
 //! // within it.
 //! let engine = Engine::default();
@@ -333,7 +330,7 @@
 //! use std::str;
 //!
 //! # use wasmtime::*;
-//! # fn main() -> anyhow::Result<()> {
+//! # fn main() -> wasmtime::Result<()> {
 //! let mut store = Store::default();
 //! let log_str = Func::wrap(&mut store, |mut caller: Caller<'_, ()>, ptr: i32, len: i32| {
 //!     // Use our `caller` context to learn about the memory export of the
@@ -427,6 +424,13 @@ pub use crate::trap::*;
 pub use crate::types::*;
 pub use crate::values::*;
 
+/// A convenience wrapper for `Result<T, anyhow::Error>`.
+///
+/// This type can be used to interact with `wasmtimes`'s extensive use
+/// of `anyhow::Error` while still not directly depending on `anyhow`.
+/// This type alias is identical to `anyhow::Result`.
+pub use anyhow::{Error, Result};
+
 #[cfg(feature = "component-model")]
 pub mod component;