Crate monostate 

  

This library implements a type macro for a zero-sized type that is Serde deserializable only from one specific value.

Examples

use monostate::MustBe;
use serde::Deserialize;

#[derive(Deserialize)]
struct Example {
    kind: MustBe!("success"),
    code: MustBe!(200),
}

The above struct would deserialize from {"kind":"success", "code":200} in JSON, but would fail the deserialization if “kind” or “code” were any other value.

This can sometimes be helpful in processing untagged enums in which the variant identification is more convoluted than what is handled by Serde’s externally tagged and internally tagged representations, for example because the variant tag has an inconsistent type or key.

use monostate::MustBe;
use serde::Deserialize;

#[derive(Deserialize)]
#[serde(untagged)]
pub enum ApiResponse {
    Success {
        success: MustBe!(true),
    },
    Error {
        kind: MustBe!("error"),
        message: String,
    },
}

Macros

MustBe

Structs

MustBeBool

MustBeChar

MustBeI8

MustBeI16

MustBeI32

MustBeI64

MustBeI128

MustBeU8

MustBeU16

MustBeU32

MustBeU64

MustBeU128

Traits

ConstStr

MustBe

Type Aliases

MustBeStr