# Module :: meta_tools [](https://github.com/emersion/stability-badges#experimental) [](https://github.com/Wandalen/wTools/actions/workflows/module_meta_tools_push.yml) [](https://docs.rs/meta_tools) [](https://gitpod.io/#RUN_PATH=.,SAMPLE_FILE=module%2Fcore%2Fmeta_tools%2Fexamples%2Fmeta_tools_trivial.rs,RUN_POSTFIX=--example%20meta_tools_trivial/https://github.com/Wandalen/wTools) [](https://discord.gg/m3YfbXpUUY) Collection of general purpose meta tools. ### Basic use-case :: variadic constructor of collections Among other useful meta tools the module aggregates variadic constructors of collections. For example macro `hmap!` for constructing a hash map. ```rust use meta_tools::*; 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 ); ``` ### Basic Use Case :: 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 use meta_tools::*; 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 examples/meta_tools_trivial cargo run ```