mirror of
https://gitee.com/fasiondog/hikyuu.git
synced 2024-12-02 11:58:21 +08:00
130 lines
2.0 KiB
C++
130 lines
2.0 KiB
C++
/*
|
||
* Null.h
|
||
*
|
||
* Created on: 2012-8-23
|
||
* Author: fasiondog
|
||
*/
|
||
|
||
#pragma once
|
||
#ifndef NULL_H_
|
||
#define NULL_H_
|
||
|
||
#include "../config.h"
|
||
#include <cstddef>
|
||
#include <limits>
|
||
#include <type_traits>
|
||
|
||
namespace hku {
|
||
|
||
/**
|
||
* @ingroup Utilities
|
||
* @addtogroup NullTools Null defines Null 值定义
|
||
* @{
|
||
*/
|
||
|
||
/**
|
||
* 提供指定给定类型的Null值
|
||
*/
|
||
template <typename T>
|
||
class Null {
|
||
public:
|
||
Null() {}
|
||
operator T() const {
|
||
return T();
|
||
}
|
||
};
|
||
|
||
/**
|
||
* 提供int的Null值
|
||
*/
|
||
template <>
|
||
class Null<int> {
|
||
public:
|
||
Null() {}
|
||
operator int() {
|
||
return (std::numeric_limits<int>::max)();
|
||
}
|
||
};
|
||
|
||
/**
|
||
* 提供unsigned int的Null值
|
||
*/
|
||
template <>
|
||
class Null<unsigned int> {
|
||
public:
|
||
Null() {}
|
||
operator unsigned int() {
|
||
return (std::numeric_limits<unsigned int>::max)();
|
||
}
|
||
};
|
||
|
||
/**
|
||
* 提供long long（64位整型）的Null值
|
||
*/
|
||
template <>
|
||
class Null<long long> {
|
||
public:
|
||
Null() {}
|
||
operator long long() {
|
||
return (std::numeric_limits<long long>::max)();
|
||
}
|
||
};
|
||
|
||
#if !defined(_MSC_VER) && !HKU_OS_OSX
|
||
/**
|
||
* int64_t Null值
|
||
*/
|
||
template <>
|
||
class Null<int64_t> {
|
||
public:
|
||
Null() {}
|
||
operator int64_t() {
|
||
return (std::numeric_limits<int64_t>::max)();
|
||
}
|
||
};
|
||
#endif
|
||
|
||
/**
|
||
* 提供unsigned long long（无符号64位整型）的Null值
|
||
*/
|
||
template <>
|
||
class Null<unsigned long long> {
|
||
public:
|
||
Null() {}
|
||
operator unsigned long long() {
|
||
return (std::numeric_limits<unsigned long long>::max)();
|
||
}
|
||
};
|
||
|
||
#if !defined(_MSC_VER)
|
||
/**
|
||
* 提供size_t的Null值
|
||
*/
|
||
template <>
|
||
class Null<size_t> {
|
||
public:
|
||
Null() {}
|
||
operator unsigned long long() {
|
||
return (std::numeric_limits<size_t>::max)();
|
||
}
|
||
};
|
||
#endif
|
||
|
||
/**
|
||
* 提供double的Null值
|
||
*/
|
||
template <>
|
||
class Null<double> {
|
||
public:
|
||
Null() {}
|
||
operator double() {
|
||
return (std::numeric_limits<double>::quiet_NaN)();
|
||
// return (std::numeric_limits<double>::max)();
|
||
}
|
||
};
|
||
|
||
/** @} */
|
||
} // namespace hku
|
||
|
||
#endif /* NULL_H_ */
|