Remove derive as default feature

.github/workflows/ci.yml

@@ -37,9 +37,9 @@ jobs:
     - name: Check formatting
       run: cargo fmt -- --check
     - name: Documentation
-      run: cargo doc --workspace
+      run: cargo doc --workspace --features netcdf/derive
     - name: Clippy
-      run: cargo clippy --workspace -- -D warnings
+      run: cargo clippy --features netcdf/derive --workspace -- -D warnings
 
   test_apt:
     name: test apt
@@ -71,10 +71,10 @@ jobs:
         toolchain: ${{ matrix.rust }}
 
     - name: Build
-      run: cargo build --verbose --workspace --exclude netcdf-src
+      run: cargo build --verbose --features netcdf/derive --workspace --exclude netcdf-src
 
     - name: Test
-      run: cargo test --verbose --workspace --exclude netcdf-src --exclude netcdf-derive
+      run: cargo test --verbose --features netcdf/derive --workspace --exclude netcdf-src --exclude netcdf-derive
 
   conda:
     name: conda
@@ -106,7 +106,7 @@ jobs:
           export HDF5_DIR="$CONDA_PREFIX"
           export NETCDF_DIR="$CONDA_PREFIX"
           [ "${{runner.os}}" != "Windows" ] && export RUSTFLAGS="-C link-args=-Wl,-rpath,$CONDA_PREFIX/lib"
-          cargo test -vv --workspace --exclude netcdf-src --exclude netcdf-derive
+          cargo test -vv --workspace --exclude netcdf-src --exclude netcdf-derive --features netcdf/derive
 
   static_builds:
     name: static builds
@@ -131,7 +131,7 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
         with: {toolchain: '${{matrix.rust}}'}
       - name: Build and test
-        run: cargo test -vv --features static --workspace --exclude netcdf-derive
+        run: cargo test -vv --features netcdf/derive,static --workspace --exclude netcdf-derive
 
   addr_san:
     name: Address sanitizer
@@ -147,4 +147,4 @@ jobs:
         env:
           RUSTFLAGS: "-Z sanitizer=address"
           RUSTDOCFLAGS: "-Z sanitizer=address"
-        run: cargo test --features netcdf-sys/static --target x86_64-unknown-linux-gnu --workspace --exclude netcdf-derive
+        run: cargo test --features netcdf-sys/static,netcdf/derive --target x86_64-unknown-linux-gnu --workspace --exclude netcdf-derive

README.md

@@ -22,7 +22,7 @@ Supported:
 * Open/Append/Create modes
 * Reading from memory
 * Unlimited dimensions
-* User defined types (enum, compound, other types requires additional work)
+* User defined types, using the feature `derive` (enum, compound, other types requires additional work)
 
 Not (yet) supported (PRs welcome):
 * Writing using memory-mapped file

netcdf/Cargo.toml

@@ -16,7 +16,7 @@ exclude = ["examples/**", "tests/**"]
 build = "build.rs"
 
 [features]
-default = ["ndarray", "derive"]
+default = ["ndarray"]
 static = ["netcdf-sys/static"]
 derive = ["dep:netcdf-derive"]
 

netcdf/src/lib.rs

@@ -95,6 +95,27 @@
 //! var.put((11.., ..), values.view())?;
 //! # Ok(()) }
 //! ```
+//!
+//! How to derive `NcTypeDescriptor` for a custom type (requires `derive` feature flag).
+//! See [NcTypeDescriptor] for additional examples.
+//!
+//! ```no_run
+//! # #[cfg(not(feature = "derive"))]
+//! # fn main() { /* This test does nothing without derive feature flag */ }
+//! # #[cfg(feature = "derive")]
+//! # fn main() -> Result<(), Box<dyn std::error::Error>> {
+//! #[repr(C)]
+//! #[derive(netcdf::NcType)]
+//! struct Foo {
+//!   bar: f64,
+//!   baz: i64,
+//! }
+//! let mut file = netcdf::create("custom.nc")?;
+//! file.add_type::<Foo>()?;
+//! let mut var = file.add_variable::<Foo>("variable", &[])?;
+//! var.put_value(Foo { bar: 1.0, baz: 2 }, ())?;
+//! # Ok(()) }
+//!
 
 #![warn(missing_docs)]
 #![allow(clippy::must_use_candidate)]

netcdf/tests/types.rs

@@ -454,6 +454,7 @@ fn char() {
 }
 
 #[test]
+#[cfg(feature = "derive")]
 fn no_subtype() {
     #[derive(netcdf::NcType)]
     #[repr(C)]