concat-idents!

This crate provides a single, easy to use macro.

Usage

Basic usage

```rust use concatidents::concatidents;

concatidents!(fnname = foo, _, bar { fn fnname() { // --snip-- } });

foo__bar(); ```

Allowed identifier parts

rust concat_idents!(fn_name = _, __ { /* underscores */ }); concat_idents!(fn_name = foo, _bar { /* identifiers */ }); concat_idents!(fn_name = "foo", "bar" { /* strings */ }); concat_idents!(fn_name = 'f', 'o', 'o' { /* characters */ }); concat_idents!(fn_name = foo, 1, bar, 2 { /* integers */ }); concat_idents!(fn_name = true, false { /* booleans */ }); concat_idents!(fn_name = "enum", bar { /* quoted reserved keywords (recommended way) */ }); concat_idents!(fn_name = r#struct, bar { /* escaped reserved keywords (not recommended, since some keywords produce error) */ });

Generating Tests

```rust macrorules! generatetest { ($method:ident($lhs:ident, $rhs:ident)) => { concatidents!(testname = $method, , $lhs, _, $rhs { #[test] fn testname() { let _ = $lhs::default().$method($rhs::default()); } }); }; }

[derive(Default)]

struct S(i32);

impl Add for S { type Output = S; fn add(self,rhs: i32) -> Self::Output { S(self.0 + rhs) } }

impl Sub for S { type Output = S; fn sub(self,rhs: i32) -> Self::Output { S(self.0 - rhs) } }

generatetest!(add(S, i32)); generatetest!(sub(S, i32)); ```

Error

This macro will throw a compile error, if: 1. an unexpected syntax is passed

rust concat_idents!({}); concat_idents!(ident {}); concat_idents!(ident = {}); concat_idents!(= foo, bar {}); concat_idents!(ident = foo, bar); ... 2. one of the identifiers is invalid

rust concat_idents!(ident = true {}); // identifiers cannot consist of only one bool concat_idents!(ident = 1 {}); // identifiers cannot consist of only one int concat_idents!(ident = 1, foo {}); // identifiers cannot start with an int concat_idents!(ident = foo, 1.0 {}); // identifiers cannot contain floats concat_idents!(ident = "enum"); // identifiers cannot consist of only one reserved keyword concat_idents!(ident = r#struct); // identifiers cannot consist of only one reserved keyword concat_idents!(ident = " space"); // identifiers cannot contain spaces concat_idents!(ident = "foo-bar🧨"); // identifiers can only contain [a-zA-Z0-9_] ...