Move UninitializedFieldError to derive_builder

.github/workflows/build.yml

@@ -49,9 +49,3 @@ jobs:
           cargo build ${{ matrix.features }} --verbose
           cargo test --no-fail-fast ${{ matrix.features }} --verbose -- --nocapture
           cargo doc
-
-      - name: no_std tests crate
-        run: |
-          cd derive_builder_no_std_tests
-          cargo build ${{ matrix.features }} --verbose
-          cargo test --no-fail-fast ${{ matrix.features }} --verbose -- --nocapture

Cargo.toml

@@ -1,2 +1,2 @@
 [workspace]
-members = ["derive_builder", "derive_builder_macro", "derive_builder_core", "derive_builder_no_std_tests"]
+members = ["derive_builder", "derive_builder_macro", "derive_builder_core"]

derive_builder/Cargo.toml

@@ -18,11 +18,10 @@ readme = "README.md"
 [features]
 default = ["std"]
 std = []
-clippy = ["derive_builder_macro/clippy", "derive_builder_core/clippy"]
+clippy = ["derive_builder_macro/clippy"]
 
 [dependencies]
 derive_builder_macro = { version = "=0.10.1", path = "../derive_builder_macro" }
-derive_builder_core = { version = "=0.10.1", path = "../derive_builder_core" }
 
 [dev-dependencies]
 pretty_assertions = "0.6.1"

derive_builder_core/src/error.rs → derive_builder/src/error.rs

@@ -1,5 +1,9 @@
+#[cfg(feature = "std")]
 use std::{error::Error, fmt};
 
+#[cfg(not(feature = "std"))]
+use core::fmt;
+
 /// Runtime error when a `build()` method is called and one or more required fields
 /// do not have a value.
 #[derive(Debug, Clone)]
@@ -23,6 +27,7 @@ impl fmt::Display for UninitializedFieldError {
     }
 }
 
+#[cfg(feature = "std")]
 impl Error for UninitializedFieldError {}
 
 impl From<&'static str> for UninitializedFieldError {

derive_builder/src/lib.rs

@@ -544,13 +544,14 @@
 #[cfg(not(feature = "std"))]
 extern crate alloc;
 
-extern crate derive_builder_core;
 extern crate derive_builder_macro;
 
+mod error;
+
 pub use derive_builder_macro::Builder;
 
 #[doc(inline)]
-pub use derive_builder_core::UninitializedFieldError;
+pub use error::UninitializedFieldError;
 
 #[doc(hidden)]
 pub mod export {

derive_builder_core/src/lib.rs

@@ -37,14 +37,11 @@ mod builder;
 mod builder_field;
 mod deprecation_notes;
 mod doc_comment;
-mod error;
 mod initializer;
 mod macro_options;
 mod options;
 mod setter;
 
-pub use error::UninitializedFieldError;
-
 pub(crate) use block::Block;
 pub(crate) use build_method::BuildMethod;
 pub(crate) use builder::Builder;