CPPScienceEngWIN/Program1_3.cpp at master · zwbproducts/CPPScienceEngWIN · GitHub

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#include <iomanip>
#include <iostream>
#include <limits>
#include <string_view>

#include "Program1_3.h"

namespace programs
{
namespace
{
	template <typename Real>
	void printFormats(std::string_view typeName, Real value)
	{
		const auto originalFlags = std::cout.flags();
		const auto originalPrecision = std::cout.precision();
		const auto precision = std::numeric_limits<Real>::max_digits10;

		std::cout << "The " << typeName << " as a decimal is "
			<< std::fixed << std::setprecision(precision) << value << '\n';
		std::cout << "The " << typeName << " as an exponential is "
			<< std::scientific << std::setprecision(precision) << value << '\n';

		std::cout.flags(originalFlags);
		std::cout.precision(originalPrecision);
	}

	template <typename Real>
	bool readAndWriteReal(std::string_view typeName, std::string_view inputFormat)
	{
		std::cout << "Enter a " << typeName << " value in " << inputFormat
			<< " format (range [" << std::numeric_limits<Real>::lowest() << ", "
			<< std::numeric_limits<Real>::max() << "]): " << std::flush;

		Real value{};
		if (!(std::cin >> value))
		{
			return false;
		}

		printFormats(typeName, value);
		return true;
	}
}

void runProgram1_3()
{
	if (!readAndWriteReal<float>("float", "decimal"))
	{
		return;
	}

	if (!readAndWriteReal<float>("float", "exponential"))
	{
		return;
	}

	if (!readAndWriteReal<double>("double", "decimal"))
	{
		return;
	}

	readAndWriteReal<double>("double", "exponential");
}
}