> Aztec.nr API reference, v6.0.0 (mainnet and testnet). Index: https://docs.aztec.network/aztec-nr-api/v6.0.0/llms.txt

# Function make_trait_impl

Module: `std::meta`

```rust
pub comptime fn make_trait_impl<Env1, Env2>(
    s: TypeDefinition,
    trait_name: Quoted,
    function_signature: Quoted,
    for_each_field: fn[Env1](Quoted) -> Quoted,
    join_fields_with: Quoted,
    body: fn[Env2](Quoted) -> Quoted,
) -> Quoted
```

`make_impl` is a helper function to make a simple impl, usually while deriving a trait. This impl has a couple assumptions:

1. The impl only has one function, with the signature `function_signature`
2. The trait itself does not have any generics.

While these assumptions are met, `make_impl` will create an impl from a TypeDefinition, automatically filling in the required generics from the type, along with the where clause. The function body is created by mapping each field with `for_each_field` and joining the results with `join_fields_with`. The result of this is passed to the `body` function for any final processing - e.g. wrapping each field in a `StructConstructor { .. }` expression.

See `derive_eq` and `derive_default` for example usage.