capy::di::ChainableConfig Concept Reference

Concept for configuration objects that transform/decorate dependencies. More...

#include <ChainableConfig.hpp>

Concept definition

template<typename Config>
concept capy::di::ChainableConfig =  
    requires() {
        typename Config::RelatedEntity;
        typename Config::RelatedKeysPack;
        Config::CONFIG_TYPE;
    }
    
    
    
    
    
    
    
    
    && std::same_as<std::remove_cv_t<decltype(Config::CONFIG_TYPE)>, ConfigType>
    && Config::CONFIG_TYPE == ConfigType::CHAINABLE

Detailed Description

Concept for configuration objects that transform/decorate dependencies.

A ChainableConfig is a compile-time concept that ensures a type can participate in the transformation pipeline. Each chainable config:

• Declares a RelatedEntity type (the type it transforms/decorates)
• Declares a RelatedKey type (used for lookup/matching in the chain)
• Implements a pipe() method that applies the transformation
• Is statically classified as ConfigType::CHAINABLE

Template Parameters

Config

The configuration type being tested.

The pipe() method signature (when enabled) should be:

Reference<RelatedEntity> auto pipe(Reference<RelatedEntity> auto entity) const;

This enables powerful decorator patterns like:

class CacheDecorator {
    using RelatedEntity = MyService;
    using RelatedKey = CacheKey;
    static constexpr ConfigType CONFIG_TYPE = ConfigType::CHAINABLE;
    
    Reference<MyService> auto pipe(Reference<MyService> auto service) const {
        return cached_service(service);
    }
};

See also

ConfigType

CreationalConfig