(C++) ApfloatToDouble

ApfloatToDouble is an apfloat example.

Technical facts

Operating system(s) or programming environment(s)

Lubuntu 15.04 (vivid)

Qt Creator 3.1.1

Console application

C++98

G++ 4.9.2

Libraries used:

STL: GNU ISO C++ Library, version 4.9.2

Qt project file: ./CppApfloatToDouble/CppApfloatToDouble.pro

`include(../../ConsoleApplicationNoWeffcpp.pri) include(../../Libraries/Boost.pri) include(../../Libraries/Apfloat.pri) SOURCES += main.cpp`

./CppApfloatToDouble/main.cpp

#pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Weffc++" #pragma GCC diagnostic ignored "-Wunused-local-typedefs" #pragma GCC diagnostic ignored "-Wunused-variable" #include <string> #include <iomanip> #include <iostream> #include <boost/lexical_cast.hpp> #include "apfloat.h" #pragma GCC diagnostic pop //Uses C++98 double ToDoubleCpp98(const apfloat& a) { std::stringstream s; s << a; double x; s >> x; return x; } //Uses apfloat and C++98 double ToDoubleApfloatCpp98(const apfloat& a) { return ap2double(a.ap); } //Uses Boost and C++98 double ToDoubleBoostCpp98(const apfloat& a) { std::stringstream s; s << a; return boost::lexical_cast<double>(s.str()); } //Uses C++11 double ToDoubleCpp11(const apfloat& a) { std::stringstream s; s << a; return std::stod(s.str()); } int main() { { const double x{12.34}; const apfloat y(x); const double a{ToDoubleCpp98(y)}; const double b{ToDoubleApfloatCpp98(y)}; const double c{ToDoubleBoostCpp98(y)}; const double d{ToDoubleCpp11(y)}; assert(a == x); assert(b == x); assert(c == x); assert(d == x); } { const double x{4818656.433841671999999998}; const apfloat y(x); const double a{ToDoubleCpp98(y)}; const double b{ToDoubleApfloatCpp98(y)}; const double c{ToDoubleBoostCpp98(y)}; const double d{ToDoubleCpp11(y)}; assert(a > 4818656.43384167 && a < 4818656.43384168); assert(b > 4818656.43384167 && b < 4818656.43384168); assert(c > 4818656.43384167 && c < 4818656.43384168); assert(d > 4818656.43384167 && d < 4818656.43384168); } }