Files
YYCCommonplace/src/yycc/constraint.hpp

79 lines
3.1 KiB
C++

#pragma once
#include "macro/class_copy_move.hpp"
#include <functional>
#include <stdexcept>
#include <algorithm>
/// @brief The namespace containing generic constraint concept used varied in other modules.
namespace yycc::constraint {
/// @brief Function prototype used in Constraint for checking whether given value is valid.
/// @details Analyze given value, and return true if value is legal, otherwise false.
template<typename T>
using FnCheck = std::function<bool(const T&)>;
/// @brief Function prototype used in Constraint for clamping given value into a valid value.
/// @details Analyze given value, return clamped value.
template<typename T>
using FnClamp = std::function<T(const T&)>;
/**
* @brief The constraint applied to settings to limit its stored value.
* @tparam T The data type this constraint need to be processed with.
* @details
* Constraint class contains various features:
* \li Check: Check whether given value is in range.
* \li Clamp: Clamp given value into valid value.
* Every instances of Constraint can have some, or none of these features.
* So it is essential to check whether instance has corresponding features before using it.
*/
template<typename T>
class Constraint {
public:
Constraint(FnCheck<T>&& fn_check, FnClamp<T>&& fn_clamp) :
fn_check(std::move(fn_check)), fn_clamp(std::move(fn_clamp)) {}
YYCC_DELETE_COPY(Constraint)
YYCC_DEFAULT_MOVE(Constraint)
/**
* @brief Perform Check feature.
* @param[in] value The valid for checking.
* @return True if valid is okey, otherwise false.
* @exception std::logic_error Raised if this feature is not supported.
*/
bool check(const T& value) const {
if (!support_check()) {
throw std::logic_error("this Constraint do not support check operation");
} else {
return fn_check(value);
}
}
/**
* @brief Perform Clamp feature.
* @param[in] value The valid for clamping.
* @return The result after clamping.
* @exception std::logic_error Raised if this feature is not supported.
*/
T clamp(const T& value) const {
if (!support_clamp()) {
throw std::logic_error("this Constraint do not support clamp operation");
} else {
return fn_clamp(value);
}
}
/// @brief Check whether this Constraint support Check feature.
/// @return True if it support, otherwise false.
bool support_check() const noexcept { return this->fn_check != nullptr; }
/// @brief Check whether this Constraint support Clamp feature.
/// @return True if it support, otherwise false.
bool support_clamp() const noexcept { return this->fn_clamp != nullptr; }
private:
/// @brief Pointer to Check feature function.
FnCheck<T> fn_check;
/// @brief Pointer to Clamp feature function.
FnClamp<T> fn_clamp;
};
} // namespace yycc::core::constraint