field

mach::validation::ValidationBuilder<T>::field

Configures validation for a field.

Description

Creates a validation builder for the specified field of T.

The returned builder may be used to add validation rules that apply to that field.

Syntax

template <typename Field>
[[nodiscard]] validation::FieldValidationBuilder<T, Field> field(Field T::* field);

Return Value

A FieldValidationBuilder for configuring validation rules for the specified field.

Template Parameters

Parameter	Description
`Field`	The type of the selected field.

Parameters

Parameter	Description
`field`	A pointer to the member field to configure.

Thread Safety

This function is not thread-safe and should only be called during validation configuration.

Example

struct RegisterRequest {
    std::string username;
    std::string email;
    int age;

    void validate(mach::ValidationBuilder<RegisterRequest>& validation) const {
        validation.field(&RegisterRequest::username)
            .length(3, 20)
            .regex(R"(^[A-Za-z0-9_]+$)");

        validation.field(&RegisterRequest::email)
            .email();

        validation.field(&RegisterRequest::age)
            .range(18, 120);
    }
};

MACH_DEFINE_JSON(RegisterRequest, username, email, age)