Initial commit

libs/math/example/test_nonfinite_loopback.cpp

@@ -0,0 +1,97 @@
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// Copyright (c) 2006 Johan Rade
+// Copyright (c) 2011 Paul A. Bristow
+
+/*!
+\file
+\brief Basic tests of native nonfinite loopback.
+
+\detail Basic loopback test outputs using the platforms built-in facets
+and reads back in, and checks if loopback OK.
+
+Using MSVC this doesn't work OK:
+input produces just "1" instead of "1.#QNAN", 1.#SNAN" or 1.#IND"!
+
+*/
+
+#include <iostream>
+using std::cout;
+using std::endl;
+#include <locale>
+using std::locale;
+#include <string>
+using std::string;
+#include <sstream>
+  using std::stringstream;
+#include <limits>
+using std::numeric_limits;
+
+int main()
+{
+   locale default_locale; // Current global locale.
+  // Try to use the default locale first.
+  // On MSVC this doesn't work.
+
+  { // Try infinity.
+    stringstream ss; // Both input and output.
+    ss.imbue(default_locale); // Redundant, of course.
+    string infs;
+    if(numeric_limits<double>::has_infinity)
+    {  // Make sure infinity is specialised for type double.
+      double inf = numeric_limits<double>::infinity();
+      ss << inf; // Output infinity.
+      infs = ss.str();  //
+    }
+    else
+    { // Need to provide a suitable string for infinity.
+     infs =  "1.#INF"; // Might suit MSVC?
+      ss << infs;
+    }
+    double r;
+    ss >> r; // Read back in.
+
+    cout << "infinity output was " << infs << endl; // "1.#INF"
+    cout << "infinity input was " << r << endl; // "1"
+  }
+
+    { // Try Quiet NaN
+    stringstream ss; // Both input and output.
+    ss.imbue(default_locale); // Redundant, of course.
+    string infs;
+    if(numeric_limits<double>::has_quiet_NaN)
+    {  // Make sure quiet NaN is specialised for type double.
+      double qnan = numeric_limits<double>::quiet_NaN();
+      ss << qnan; // Output quiet_NaN.
+      infs = ss.str();  //
+    }
+    else
+    { // Need to provide a suitable string for quiet_NAN.
+     infs =  "1.#QNAN";
+      ss << infs;
+    }
+    double r;
+    ss >> r; // Read back in.
+
+    cout << "quiet_NaN output was " << infs << endl; // "1.#QNAN"
+    cout << "quiet_NaN input was " << r << endl; // "1#"
+  }
+
+
+} // int main()
+
+/*
+
+Output (MSVC Version 10.0):
+
+
+  infinity output was 1.#INF
+  infinity input was 1
+  quiet_NaN output was 1.#QNAN
+  quiet_NaN input was 1
+
+
+*/
+