Subject: [Boost-commit] svn:boost r71271 - trunk/libs/math/example
From: pbristow_at_[hidden]
Date: 2011-04-15 09:37:22
Author: pbristow
Date: 2011-04-15 09:37:21 EDT (Fri, 15 Apr 2011)
New Revision: 71271
URL: http://svn.boost.org/trac/boost/changeset/71271
Log:
First nonfinite example nonfinite_signaling_NaN.cpp.
Added:
trunk/libs/math/example/nonfinite_signaling_NaN.cpp (contents, props changed)
Added: trunk/libs/math/example/nonfinite_signaling_NaN.cpp
==============================================================================
--- (empty file)
+++ trunk/libs/math/example/nonfinite_signaling_NaN.cpp 2011-04-15 09:37:21 EDT (Fri, 15 Apr 2011)
@@ -0,0 +1,174 @@
+// 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 Tests of nonfinite signaling NaN loopback.
+
+\detail nonfinite signaling NaN
+test outputs using nonfinite facets
+(output and input) and reads back in, and checks if loopback OK.
+
+Not expected to work on all platforms (if any). But shows that on MSVC,
+this legacy locale can ensure a consistent quiet NaN input from representations
+"1.#QNAN", "1.#SNAN" and "1.#IND"
+
+*/
+
+#ifdef _MSC_VER
+# pragma warning(disable : 4702)
+#endif
+
+#include <boost/math/special_functions/nonfinite_num_facets.hpp>
+using boost::math::nonfinite_num_get;
+using boost::math::nonfinite_num_put;
+
+#include <iostream>
+using std::cout;
+using std::endl;
+
+#include <locale>
+using std::locale;
+
+#include <string>
+using std::string;
+
+#include <sstream>
+ using std::stringstream;
+ using std::istringstream;
+
+#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 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"
+ }
+
+ { // Try Signaling NaN
+ stringstream ss; // Both input and output.
+ ss.imbue(default_locale); // Redundant, of course.
+ string infs;
+ if(numeric_limits<double>::has_signaling_NaN)
+ { // Make sure signaling NaN is specialised for type double.
+ double qnan = numeric_limits<double>::signaling_NaN();
+ ss << qnan; // Output signaling_NaN.
+ infs = ss.str(); //
+ }
+ else
+ { // Need to provide a suitable string for signaling NaN.
+ infs = "1.#SNAN";
+ ss << infs;
+ }
+ double r;
+ ss >> r; // Read back in.
+
+ cout << "signaling_NaN output was " << infs << endl; // "1.#QNAN" (or "1.#SNAN"?)
+ cout << "signaling_NaN input was " << r << endl; // "1"
+ }
+
+ // Create legacy_locale and store the nonfinite_num_get facet (with legacy flag) in it.
+ locale legacy_locale(default_locale, new nonfinite_num_get<char>(boost::math::legacy));
+ // Note that the legacy flag has no effect on the nonfinite_num_put output facet.
+
+ cout << "Use legacy locale." << endl;
+
+ { // Try infinity.
+ stringstream ss; // Both input and output.
+ ss.imbue(legacy_locale);
+ 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";
+ ss << infs;
+ }
+ double r;
+ ss >> r; // Read back in.
+
+ cout << "infinity output was " << infs << endl; // "1.#INF"
+ cout << "infinity input was " << r << endl; // "1.#INF"
+ }
+
+ { // Try input of "1.#SNAN".
+ //double inf = numeric_limits<double>::signaling_NaN(); // Assigns "1.#QNAN" on MSVC.
+ // So must use explicit string "1.#SNAN" instead.
+ stringstream ss; // Both input and output.
+ ss.imbue(legacy_locale);
+ string s = "1.#SNAN";
+
+ ss << s; // Write out.
+ double r;
+
+ ss >> r; // Read back in.
+
+ cout << "SNAN output was " << s << endl; // "1.#SNAN"
+ cout << "SNAN input was " << r << endl; // "1.#QNAN"
+ }
+
+ { // Try input of "1.#IND" .
+ stringstream ss; // Both input and output.
+ ss.imbue(legacy_locale);
+ string s = "1.#IND";
+ ss << s; // Write out.
+ double r;
+ ss >> r; // Read back in.
+
+ cout << "IND output was " << s << endl; // "1.#IND"
+ cout << "IND input was " << r << endl; // "1.#QNAN"
+ }
+
+} // int main()
+
+/*
+
+Output:
+ nonfinite_signaling_NaN.vcxproj -> J:\Cpp\fp_facet\fp_facet\Debug\nonfinite_signaling_NaN.exe
+
+ quiet_NaN output was 1.#QNAN
+ quiet_NaN input was 1
+ signaling_NaN output was 1.#QNAN
+ signaling_NaN input was 1
+ Use legacy locale.
+ infinity output was 1.#INF
+ infinity input was 1.#INF
+ SNAN output was 1.#SNAN
+ SNAN input was 1.#QNAN
+ IND output was 1.#IND
+ IND input was 1.#QNAN
+
+
+*/
+