关于C#：对浮点类型的编译时操作

Compile time operations on floating point types

我有一些静态const浮点成员变量，我想在这些变量上进行一些静态断言的编译。以下代码在gcc中编译，但在clang和Visual Studio中均失败：

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#include <boost/static_assert.hpp>
#include <iostream>

template<typename Scalar>
class ProbModel {
public:
static const Scalar probA;
static const Scalar probB;

private:
BOOST_STATIC_ASSERT_MSG(probA < 1,"Weird Parameter");
BOOST_STATIC_ASSERT_MSG(probB < 1,"Weird Parameter");
BOOST_STATIC_ASSERT_MSG(probA < probB,"Weird Parameter");
};

// Initializations
template<typename Scalar> const Scalar
ProbModel<Scalar>::probA = 0.3;

template<typename Scalar> const Scalar
ProbModel<Scalar>::probB = 0.6;

int main(int argc, char* argv[]) {
typedef ProbModel<float> Modelf;
std::cout <<"ProbA =" << Modelf::probA << std::endl;
}

我在Visual Studio 2013和Clang中收到抱怨常量表达式的静态断言语句错误：

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2>..\\static_assert_experiments.cpp(11): error C2057: expected constant expression
2>..\\static_assert_experiments.cpp(12): error C2057: expected constant expression
2>..\\static_assert_experiments.cpp(13): error C2057: expected constant expression

一个非c 11的解决方案将受到高度赞赏。还有其他方法可以对静态参数进行此类检查吗？

相关讨论

如注释中的dyp所述，不能在常量表达式中使用浮点类型的变量。可能的解决方法是使用有理数。

std::ratio是C 11，但可以轻松移植到C 03

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template<typename Scalar>
class ProbModel {
public:

static Scalar getProbA() { return Scalar(probA::num) / probA::den; }
static Scalar getProbB() { return Scalar(probB::num) / probB::den; }

private:
typedef std::ratio<3, 10> probA; // 0.3
typedef std::ratio<6, 10> probB; // 0.6

BOOST_STATIC_ASSERT_MSG(probA::num < probA::den,"Weird Parameter");
BOOST_STATIC_ASSERT_MSG(probB::num < probB::den,"Weird Parameter");
BOOST_STATIC_ASSERT_MSG(probA::num * probB::den < probB::num * probA::den,"Weird Parameter");
};