Technical facts

Operating system(s) or programming environment(s)

Lubuntu 15.04 (vivid)

IDE(s):

Qt Creator 3.1.1

Project type:

Console application

C++ standard:

C++98

Compiler(s):

G++ 4.9.2

Libraries used:

STL: GNU ISO C++ Library, version 4.9.2

Qt project file: ./CppStdSetPrecisionExample1/CppStdSetPrecisionExample1.pro


TEMPLATE = app

CONFIG += console

CONFIG -= app_bundle

CONFIG -= qt



SOURCES += main.cpp

./CppStdSetPrecisionExample1/main.cpp


#include <cassert>

#include <iostream>

#include <iomanip>

#include <sstream>



const std::string FormatDigitsBehindTheComma(const double x, const std::size_t n)

{

  std::stringstream s;

  s << std::setprecision(n) << std::fixed << x;

  const std::string t = s.str();

  return t;

}



int main()

{

  const double x = 4.0 / 3.0;

  assert(FormatDigitsBehindTheComma(x, 0) == std::string("1"));

  assert(FormatDigitsBehindTheComma(x, 1) == std::string("1.3"));

  assert(FormatDigitsBehindTheComma(x, 2) == std::string("1.33"));

  assert(FormatDigitsBehindTheComma(x, 3) == std::string("1.333"));

  assert(FormatDigitsBehindTheComma(x, 4) == std::string("1.3333"));

  assert(FormatDigitsBehindTheComma(x, 5) == std::string("1.33333"));

  assert(FormatDigitsBehindTheComma(x, 6) == std::string("1.333333"));

  assert(FormatDigitsBehindTheComma(x, 7) == std::string("1.3333333"));

  assert(FormatDigitsBehindTheComma(x, 8) == std::string("1.33333333"));

  assert(FormatDigitsBehindTheComma(x, 9) == std::string("1.333333333"));

  assert(FormatDigitsBehindTheComma(x,10) == std::string("1.3333333333"));

  assert(FormatDigitsBehindTheComma(x,11) == std::string("1.33333333333"));

  assert(FormatDigitsBehindTheComma(x,12) == std::string("1.333333333333"));

  assert(FormatDigitsBehindTheComma(x,13) == std::string("1.3333333333333"));

  assert(FormatDigitsBehindTheComma(x,14) == std::string("1.33333333333333"));

  assert(FormatDigitsBehindTheComma(x,15) == std::string("1.333333333333333"));

  assert(FormatDigitsBehindTheComma(x,16) == std::string("1.3333333333333333"));

  //assert(FormatDigitsBehindTheComma(x,17) == std::string("1.33333333333333333")); //Fails due to precision of double

}

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(C++) StdSetPrecisionExample1

Technical facts

Qt project file: ./CppStdSetPrecisionExample1/CppStdSetPrecisionExample1.pro

./CppStdSetPrecisionExample1/main.cpp