fix: Remove once_cell dependency from derive

With being able to accept owned types now, `clap_derive` no longer needs `once_cell` to make dynamic data static. This helps towards clap-rs#1365, clap-rs#2037
epage · Aug 16, 2022 · 429143a · 429143a
1 parent 91e55c6
commit 429143a
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Showing 3 changed files with 10 additions and 32 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -69,7 +69,7 @@ suggestions = ["dep:strsim"]
 
 # Optional
 deprecated = ["clap_derive?/deprecated"] # Guided experience to prepare for next breaking release (at different stages of development, this may become default)
-derive = ["clap_derive", "dep:once_cell"]
+derive = ["clap_derive"]
 cargo = ["dep:once_cell"] # Disable if you're not using Cargo, enables Cargo-env-var-dependent macros
 wrap_help = ["dep:terminal_size", "textwrap/terminal_size"]
 env = [] # Use environment variables during arg parsing

diff --git a/clap_derive/src/attrs.rs b/clap_derive/src/attrs.rs
@@ -504,11 +504,10 @@ impl Attrs {
                         })
                     } else {
                         quote_spanned!(ident.span()=> {
-                            static DEFAULT_VALUE: clap::__macro_refs::once_cell::sync::Lazy<String> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
+                            {
                                 let val: #ty = #val;
                                 ::std::string::ToString::to_string(&val)
-                            });
-                            &*DEFAULT_VALUE
+                            }
                         })
                     };
 
@@ -558,10 +557,7 @@ impl Attrs {
 
                                 }
 
-                                static DEFAULT_VALUES: clap::__macro_refs::once_cell::sync::Lazy<Vec<&str>> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
-                                    iter_to_vals(#expr)
-                                });
-                                DEFAULT_VALUES.iter().copied()
+                                iter_to_vals(#expr)
                             }
                         })
                     } else {
@@ -575,14 +571,7 @@ impl Attrs {
 
                                 }
 
-                                static DEFAULT_STRINGS: clap::__macro_refs::once_cell::sync::Lazy<Vec<::std::string::String>> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
-                                    iter_to_vals(#expr)
-                                });
-
-                                static DEFAULT_VALUES: clap::__macro_refs::once_cell::sync::Lazy<Vec<&str>> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
-                                    DEFAULT_STRINGS.iter().map(::std::string::String::as_str).collect()
-                                });
-                                DEFAULT_VALUES.iter().copied()
+                                iter_to_vals(#expr)
                             }
                         })
                     };
@@ -619,11 +608,10 @@ impl Attrs {
                         })
                     } else {
                         quote_spanned!(ident.span()=> {
-                            static DEFAULT_VALUE: clap::__macro_refs::once_cell::sync::Lazy<::std::ffi::OsString> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
+                            {
                                 let val: #ty = #val;
                                 ::std::ffi::OsString::from(val)
-                            });
-                            &*DEFAULT_VALUE
+                            }
                         })
                     };
 
@@ -674,10 +662,7 @@ impl Attrs {
 
                                 }
 
-                                static DEFAULT_VALUES: clap::__macro_refs::once_cell::sync::Lazy<Vec<&::std::ffi::OsStr>> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
-                                    iter_to_vals(#expr)
-                                });
-                                DEFAULT_VALUES.iter().copied()
+                                iter_to_vals(#expr)
                             }
                         })
                     } else {
@@ -691,14 +676,7 @@ impl Attrs {
 
                                 }
 
-                                static DEFAULT_OS_STRINGS: clap::__macro_refs::once_cell::sync::Lazy<Vec<::std::ffi::OsString>> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
-                                    iter_to_vals(#expr)
-                                });
-
-                                static DEFAULT_VALUES: clap::__macro_refs::once_cell::sync::Lazy<Vec<&::std::ffi::OsStr>> = clap::__macro_refs::once_cell::sync::Lazy::new(|| {
-                                    DEFAULT_OS_STRINGS.iter().map(::std::ffi::OsString::as_os_str).collect()
-                                });
-                                DEFAULT_VALUES.iter().copied()
+                                iter_to_vals(#expr)
                             }
                         })
                     };

diff --git a/src/lib.rs b/src/lib.rs
@@ -131,7 +131,7 @@ pub mod _tutorial;
 
 #[doc(hidden)]
 pub mod __macro_refs {
-    #[cfg(any(feature = "derive", feature = "cargo"))]
+    #[cfg(feature = "cargo")]
     #[doc(hidden)]
     pub use once_cell;
 }