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

# Module meta

Module: `std::meta`

## Modules

- [ctstring](/aztec-nr-api/v6.0.0/std/meta/ctstring/index.md)
- [expr](/aztec-nr-api/v6.0.0/std/meta/expr/index.md): Contains methods on the built-in `Expr` type for quoted, syntactically valid expressions.
- [function_def](/aztec-nr-api/v6.0.0/std/meta/function_def/index.md)
- [item_visibility](/aztec-nr-api/v6.0.0/std/meta/item_visibility/index.md)
- [op](/aztec-nr-api/v6.0.0/std/meta/op/index.md)
- [typ](/aztec-nr-api/v6.0.0/std/meta/typ/index.md): Contains methods on the built-in `Type` type used for representing a type in the source program.
- [type_def](/aztec-nr-api/v6.0.0/std/meta/type_def/index.md)

## Type aliases

- [DeriveFunction](/aztec-nr-api/v6.0.0/std/meta/type.DeriveFunction.md)

## Functions

- [derive](/aztec-nr-api/v6.0.0/std/meta/fn.derive.md)

- [derive_via](/aztec-nr-api/v6.0.0/std/meta/fn.derive_via.md)

- [error](/aztec-nr-api/v6.0.0/std/meta/fn.error.md): Issues an error diagnostic at the given location with the given primary message and an optional secondary message. Unlike a comptime panic, current execution will continue allowing possibly multiple errors to be issued.

- [make_trait_impl](/aztec-nr-api/v6.0.0/std/meta/fn.make_trait_impl.md): `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.

- [type_of](/aztec-nr-api/v6.0.0/std/meta/fn.type_of.md): Returns the type of any value

- [unquote](/aztec-nr-api/v6.0.0/std/meta/fn.unquote.md): Calling unquote as a macro (via `unquote!(arg)`) will unquote its argument. Since this is the effect `!` already does, `unquote` itself does not need to do anything besides return its argument.

- [warn](/aztec-nr-api/v6.0.0/std/meta/fn.warn.md): Issues a warning diagnostic at the given location with the given primary message and an optional secondary message. Execution continues after this function is called.