# Module :: meta_tools [](https://github.com/emersion/stability-badges#experimental) [](https://github.com/Wandalen/wTools/actions/workflows/ModuleMetaToolsPush.yml) [](https://docs.rs/meta_tools) [](https://discord.gg/m3YfbXpUUY) Collection of general purpose meta tools. ### Sample :: variadic constructor of collections Among other useful meta tools the module aggregates variadtic constructors of collections. For example macro `hmap!` for constructing a hash map. ```rust #[ cfg( feature = "collection_make" ) ] { use meta_tools_min::*; let meta_map = hmap! { 3 => 13 }; let mut std_map = std::collections::HashMap::new(); std_map.insert( 3, 13 ); assert_eq!( meta_map, std_map ); } ``` ### Sample :: function-style call Apply a macro for each element of a list. Macro `for_each` may be called either in function-style way or in map-style way. Pass name of macro to apply to elements as the first arguments and elements after the macro name. Use comma as delimiter. ```rust #[ cfg( feature = "for_each" ) ] { use meta_tools_min::*; for_each!( dbg, "a", "b", "c" ); // generates dbg!( "a" ); dbg!( "b" ); dbg!( "c" ); } ``` ### To add to your project ```sh cargo add meta_tools ``` ### Try out from the repository ```sh git clone https://github.com/Wandalen/wTools cd wTools cd sample/rust/meta_tools_trivial cargo run ```