1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
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
*/
|
