Squashed 'third_party/boostorg/format/' content from commit a1c6137
Change-Id: I7c2f1d4813c1e733fcf553b4ed9c418e661b0ea8
git-subtree-dir: third_party/boostorg/format
git-subtree-split: a1c613764dd96f97749e1e059c80f0f3515fcf0b
diff --git a/benchmark/Jamfile b/benchmark/Jamfile
new file mode 100644
index 0000000..0a420ab
--- /dev/null
+++ b/benchmark/Jamfile
@@ -0,0 +1,27 @@
+# Boost.Format Library benchmark Jamfile
+#
+# Copyright (c) 2003 Samuel Krempp
+#
+# Distributed under the Boost Software License, Version 1.0.
+# See www.boost.org/LICENSE_1_0.txt
+#
+
+project libs/format/benchmark
+ : requirements
+ <toolset>msvc:<define>_CRT_SECURE_NO_WARNINGS
+ ;
+
+exe bench_format_no_locale
+ : bench_format.cpp
+ : <define>BOOST_NO_STD_LOCALE <location-prefix>no_locale
+ ;
+
+exe bench_format_normal
+ : bench_format.cpp
+ : <location-prefix>normal
+ ;
+
+exe bench_format_no_reuse_stream
+ : bench_format.cpp
+ : <include>alts <define>BOOST_FORMAT_NO_OSS_MEMBER <location-prefix>no_reuse_stream
+ ;
diff --git a/benchmark/bench_format.cpp b/benchmark/bench_format.cpp
new file mode 100644
index 0000000..393df75
--- /dev/null
+++ b/benchmark/bench_format.cpp
@@ -0,0 +1,356 @@
+// -*- C++ -*-
+// Boost general library 'format' ---------------------------
+// See http://www.boost.org for updates, documentation, and revision history.
+
+// Copyright (c) 2001 Samuel Krempp
+// krempp@crans.ens-cachan.fr
+// 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)
+
+// several suggestions from Jens Maurer
+
+// ------------------------------------------------------------------------------
+// bench_variants.cc : do the same task, with sprintf, stream, and format
+// and compare their times.
+
+// This benchmark is provided purely for information.
+// It might not even compile as-is,
+// or not give any sensible results.
+// (e.g., it expects sprintf to be POSIX compliant)
+
+// ------------------------------------------------------------------------------
+
+
+#include <iostream>
+#include <iomanip>
+#include <cstdio> // sprintf
+#include <cstring>
+#include <fstream>
+#include <cmath> // floor
+#include <boost/timer.hpp>
+#include <vector>
+
+#include <boost/format.hpp>
+
+// portable /dev/null stream equivalent, by James Kanze, http://www.gabi-soft.de
+class NulStreambuf : public std::streambuf
+{
+public:
+ NulStreambuf() {
+ setp( dummyBuffer , dummyBuffer + 64 ) ;
+ }
+ virtual int overflow( int c );
+ virtual int underflow();
+private:
+ char dummyBuffer[ 64 ] ;
+} ;
+
+class NulStream : public std::basic_ostream<char, std::char_traits<char> >
+{
+public:
+ NulStream();
+ virtual ~NulStream();
+ NulStreambuf* rdbuf() {
+ return static_cast< NulStreambuf* >(
+ ((std::basic_ostream<char, std::char_traits<char> > *) this) -> rdbuf() ) ;
+ }
+} ;
+
+
+//-------------------------------------------------------------------------------------
+// NulStream implementation
+
+NulStream::NulStream() : std::basic_ostream<char, std::char_traits<char> > (NULL) {
+ init( new NulStreambuf ) ;
+}
+
+NulStream::~NulStream() {
+ delete rdbuf() ;
+}
+
+int NulStreambuf::underflow(){ return std::ios::traits_type::eof();
+}
+
+int NulStreambuf::overflow( int c ){
+ setp( dummyBuffer , dummyBuffer + 64 ) ;
+ return (c == std::ios::traits_type::eof()) ? '\0' : c ;
+}
+
+
+
+// -------------------------------------------------------------------------------------
+
+namespace benchmark {
+
+static int NTests = 300000;
+
+//static std::stringstream nullStream;
+static NulStream nullStream;
+static double tstream, tpf;
+//static const std::string fstring="%3$#x %1$20.10E %2$g %3$d \n";
+static const std::string fstring="%3$0#6x %1$20.10E %2$g %3$0+5d \n";
+static const double arg1=45.23;
+static const double arg2=12.34;
+static const int arg3=23;
+static const std::string res =
+"0x0017 4.5230000000E+01 12.34 +0023 \n";
+//static const std::string res = "23.0000 4.5230000000E+01 12.34 23 \n";
+
+void test_sprintf();
+void test_nullstream();
+void test_opti_nullstream();
+void test_parsed_once_format();
+void test_reused_format();
+void test_format();
+void test_try1();
+void test_try2();
+
+void test_sprintf()
+{
+ using namespace std;
+
+ vector<char> bufr;
+ bufr.reserve(4000);
+ char *buf = &bufr[0];
+
+ // Check that sprintf is Unix98 compatible on the platform :
+ sprintf(buf, fstring.c_str(), arg1, arg2, arg3);
+ if( strncmp( buf, res.c_str(), res.size()) != 0 ) {
+ cerr << endl << buf;
+ }
+ // time the loop :
+ boost::timer chrono;
+ for(int i=0; i<NTests; ++i) {
+ sprintf(buf, fstring.c_str(), arg1, arg2, arg3);
+ }
+ tpf=chrono.elapsed();
+ cout << left << setw(20) <<"printf time"<< right <<":" << tpf << endl;
+}
+
+void test_try1()
+{
+ using namespace std;
+ boost::io::basic_oaltstringstream<char> oss;
+ oss << boost::format(fstring) % arg1 % arg2 % arg3;
+ boost::timer chrono;
+ size_t dummy=0;
+ for(int i=0; i<NTests; ++i) {
+ dummy += oss.cur_size();
+ }
+ double t = chrono.elapsed();
+ cout << left << setw(20) <<"try1 time"<< right <<":" << setw(5) << t
+ << ", = " << t / tpf << " * printf "
+ << ", = " << t / tstream << " * nullStream \n";
+}
+
+void test_try2()
+{
+ using namespace std;
+ boost::io::basic_oaltstringstream<char> oss;
+ oss << boost::format(fstring) % arg1 % arg2 % arg3;
+ oss << "blas 34567890GGGGGGGGGGGGGGGGGGGGGGGGGGGGggggggggggggggggggggggggggg " << endl;
+ string s = oss.cur_str();
+ oss << s << s << s;
+ oss.clear_buffer();
+ oss << s << s;
+ s = oss.cur_str();
+ boost::timer chrono;
+ size_t dummy=0;
+ for(int i=0; i<NTests; ++i) {
+ dummy += oss.cur_size();
+ }
+ double t = chrono.elapsed();
+ cout << left << setw(20) <<"try2 time"<< right <<":" << setw(5) << t
+ << ", = " << t / tpf << " * printf "
+ << ", = " << t / tstream << " * nullStream \n";
+}
+
+void do_stream(std::ostream& os) {
+ using namespace std;
+ std::ios_base::fmtflags f = os.flags();
+ os << hex << showbase << internal << setfill('0') << setw(6) << arg3
+ << dec << noshowbase << right << setfill(' ')
+ << " "
+ << scientific << setw(20) << setprecision(10) << uppercase << arg1
+ << setprecision(6) << nouppercase ;
+ os.flags(f);
+ os << " " << arg2 << " "
+ << showpos << setw(5) << internal << setfill('0') << arg3 << " \n" ;
+ os.flags(f);
+}
+
+void test_nullstream()
+{
+ using namespace std;
+ boost::timer chrono;
+ boost::io::basic_oaltstringstream<char> oss;
+
+ {
+ do_stream(oss);
+ if(oss.str() != res ) {
+ cerr << endl << oss.str() ;
+ }
+ }
+
+ for(int i=0; i<NTests; ++i) {
+ do_stream(nullStream);
+ }
+
+// for(int i=0; i<NTests; ++i) {
+// std::ios_base::fmtflags f0 = nullStream.flags();
+// nullStream << hex << showbase << arg3
+// << dec << noshowbase << " "
+// << scientific << setw(20) << setprecision(10) << uppercase << arg1
+// << setprecision(0);
+// nullStream.flags(f0);
+// nullStream << " " << arg2 << " " << arg3 << " \n" ;
+
+// }
+ double t = chrono.elapsed();
+ cout << left << setw(20) <<"ostream time"<< right <<":" << setw(5) << t
+ << ", = " << t / tpf << " * printf \n";
+ tstream = t;
+}
+
+void test_opti_nullstream()
+{
+ using namespace std;
+ boost::timer chrono;
+ boost::io::basic_oaltstringstream<char> oss;
+ //static const std::string fstring="%3$#x %1$20.10E %2$g %3$d \n";
+
+ std::ios_base::fmtflags f0 = oss.flags(), f1, f2;
+ streamsize p0 = oss.precision();
+ {
+ oss << hex << showbase;
+ f1 = oss.flags();
+ oss << arg3;
+
+ oss.flags(f0);
+ oss << " " << scientific << setw(20) << setprecision(10) << uppercase;
+ f2 = oss.flags();
+ oss << arg1;
+
+ oss.flags(f0); oss.precision(p0);
+ oss << " " << arg2 << " " << arg3 << " \n" ;
+
+ if(oss.str() != res ) {
+ cerr << endl << oss.str() ;
+ }
+ }
+
+ for(int i=0; i<NTests; ++i) {
+ nullStream.flags(f1);
+ nullStream << arg3;
+
+ nullStream << setw(20) << setprecision(10);
+ nullStream.flags(f2);
+ nullStream << arg1;
+
+ nullStream.flags(f0); nullStream.precision(p0);
+ nullStream << " " << arg2 << " " << arg3 << " \n" ;
+ }
+ double t = chrono.elapsed();
+ cout << left << setw(20) <<"opti-stream time"<< right <<":" << setw(5) << t
+ << ", = " << t / tpf << " * printf \n";
+ // tstream = t;
+}
+
+void test_parsed_once_format()
+{
+ using namespace std;
+ static const boost::format fmter(fstring);
+
+ boost::io::basic_oaltstringstream<char> oss;
+ oss << boost::format(fmter) % arg1 % arg2 % arg3 ;
+ if( oss.str() != res ) {
+ cerr << endl << oss.str();
+ }
+
+ // not only is the format-string parsed once,
+ // but also the buffer of the internal stringstream is already allocated.
+
+ boost::timer chrono;
+ for(int i=0; i<NTests; ++i) {
+ nullStream << boost::format(fmter) % arg1 % arg2 % arg3;
+ }
+ double t=chrono.elapsed();
+ cout << left << setw(20) <<"parsed-once time"<< right <<":" << setw(5) << t
+ << ", = " << t / tpf << " * printf "
+ << ", = " << t / tstream << " * nullStream \n";
+}
+
+void test_reused_format()
+{
+ using namespace std;
+ boost::io::basic_oaltstringstream<char> oss;
+ oss << boost::format(fstring) % arg1 % arg2 % arg3;
+ if(oss.str() != res ) {
+ cerr << endl << oss.str();
+ }
+
+ boost::timer chrono;
+ boost::format fmter;
+ for(int i=0; i<NTests; ++i) {
+ nullStream << fmter.parse(fstring) % arg1 % arg2 % arg3;
+ }
+ double t = chrono.elapsed();
+ cout << left << setw(20) <<"reused format time"<< right <<":" << setw(5) << t
+ << ", = " << t / tpf << " * printf "
+ << ", = " << t / tstream << " * nullStream \n";
+}
+
+void test_format()
+{
+ using namespace std;
+ boost::io::basic_oaltstringstream<char> oss;
+ oss << boost::format(fstring) % arg1 % arg2 % arg3;
+ if(oss.str() != res ) {
+ cerr << endl << oss.str();
+ }
+
+ boost::timer chrono;
+ for(int i=0; i<NTests; ++i) {
+ nullStream << boost::format(fstring) % arg1 % arg2 % arg3;
+ }
+ double t = chrono.elapsed();
+ cout << left << setw(20) <<"format time"<< right <<":" << setw(5) << t
+ << ", = " << t / tpf << " * printf "
+ << ", = " << t / tstream << " * nullStream \n";
+}
+
+} // benchmark
+
+int main(int argc, char * argv[]) {
+ using namespace benchmark;
+ using namespace boost;
+ using namespace std;
+ const string::size_type npos = string::npos;
+
+ string choices = "";
+ if (1<argc) {
+ choices = (argv[1]); // profiling is easier launching only one.
+ NTests = 1000 * 1000; // andmoreprecise with many iterations
+ cout << "choices (" << choices << ") \n";
+ }
+
+ if (choices == "" || choices.find('p') != npos)
+ test_sprintf();
+ if (choices == "" || choices.find('n') != npos)
+ test_nullstream();
+ if (choices == "" || choices.find('1') != npos)
+ test_parsed_once_format();
+ if (choices == "" || choices.find('r') != npos)
+ test_reused_format();
+ if (choices == "" || choices.find('f') != npos)
+ test_format();
+ if (choices.find('t') != npos)
+ test_try1();
+ if (choices.find('y') != npos)
+ test_try2();
+ if (choices.find('o') != npos)
+ test_opti_nullstream();
+ return 0;
+}
+
diff --git a/benchmark/results.txt b/benchmark/results.txt
new file mode 100644
index 0000000..4a884de
--- /dev/null
+++ b/benchmark/results.txt
@@ -0,0 +1,293 @@
+// Copyright (c) 2001 Samuel Krempp
+// krempp@crans.ens-cachan.fr
+// Distributed under the Boost Software License, Version 1.0. (See accompany-
+// ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// This benchmark is provided purely for information.
+// It might not even compile as-is,
+// or not give any sensible results.
+// (e.g., it expects sprintf to be POSIX compliant)
+
+ new results ( with outsstream vs. stringstream)
+
+bjam -sTOOLS="gcc intel-linux-7.1" -sBUILD="release"
+
+( -sBUILD="profile" for profiling..)
+
+
+ "_no_reuse_stream" "_stringstr" "_strstream" _no_locale
+
+intel-linux-7.1
+
+for comp in gcc ; do
+ echo "\n------------------- Compiler $comp : ---------------- "
+ for var in _overloads _basicfmt _normal; do
+ echo "\n-- Variant **" $var "**" :
+ texe=$EXEBOOST/libs/format/benchmark/bench_format${var}/${comp}/release/bench_format${var} ;
+ ls -l $texe;
+ $texe
+ done
+done
+
+
+// stringstream recréé chaque fois.
+-- Variant ** _normal ** :
+-rwx--x--x 1 sam users 61952 Sep 17 03:13 /home/data/zStore/BBoost/bin/boost//libs/format/benchmark/bench_format_normal/gcc/release/bench_format_normal
+printf time :2.16
+ostream time : 3.69, = 1.70833 * printf
+parsed-once time : 8.45, = 3.91204 * printf , = 2.28997 * nullStream
+reused format time :10.94, = 5.06481 * printf , = 2.96477 * nullStream
+format time :10.97, = 5.0787 * printf , = 2.9729 * nullStream
+
+
+Pour le parsing. step 1 : scan_not + str2int (version Iter const& qques % mieux)
+
+------------------- Compiler gcc : ----------------
+
+-- Variant ** _overloads ** :
+-rwx--x--x 1 sam users 52864 2003-09-12 02:59 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_overloads/gcc/release/bench_format_overloads
+printf time :2.21
+ostream time : 3.57, = 1.61538 * printf
+parsed-once time : 4.93, = 2.23077 * printf , = 1.38095 * nullStream
+reused format time : 9.25, = 4.18552 * printf , = 2.59104 * nullStream
+format time :10.33, = 4.67421 * printf , = 2.89356 * nullStream
+
+-- Variant ** _basicfmt ** :
+-rwx--x--x 1 sam users 52864 2003-09-12 03:00 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_basicfmt/gcc/release/bench_format_basicfmt
+printf time :2.2
+ostream time : 3.57, = 1.62273 * printf
+parsed-once time : 4.85, = 2.20455 * printf , = 1.35854 * nullStream
+reused format time : 9.25, = 4.20455 * printf , = 2.59104 * nullStream
+format time :10.29, = 4.67727 * printf , = 2.88235 * nullStream
+
+-- Variant ** _normal ** :
+-rwx--x--x 1 sam users 53088 2003-09-12 03:00 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_normal/gcc/release/bench_format_normal
+printf time :2.27
+ostream time : 3.47, = 1.52863 * printf
+parsed-once time : 4.79, = 2.11013 * printf , = 1.3804 * nullStream
+reused format time : 9.88, = 4.35242 * printf , = 2.84726 * nullStream
+format time :10.97, = 4.8326 * printf , = 3.16138 * nullStream
+
+-------------------------------------------------------------------------------------------------
+Overload : int, double char * -> put_simple :
+#if defined(BOOST_FORMAT_OVERLOADS)
+ template<class T>
+ basic_format& operator%(const char* x)
+ { return io::detail::feed_overloaded(*this,x); }
+ template<class T>
+ basic_format& operator%(const double x)
+ { return io::detail::feed_overloaded(*this,x); }
+ template<class T>
+ basic_format& operator%(const int x)
+ { return io::detail::feed_overloaded(*this,x); }
+#endif
+
+ // put overloads for common types (-> faster)
+ template< class Ch, class Tr, class T>
+ void put_simple( T x,
+ const format_item<Ch, Tr>& specs,
+ std::basic_string<Ch, Tr> & res,
+ io::basic_outsstream<Ch, Tr>& oss_ )
+ {
+ typedef std::basic_string<Ch, Tr> string_t;
+ typedef format_item<Ch, Tr> format_item_t;
+
+ specs.fmtstate_.apply_on(oss_);
+ const std::ios_base::fmtflags fl=oss_.flags();
+ const std::streamsize w = oss_.width();
+
+ if(w!=0)
+ oss_.width(0);
+ put_last( oss_, x);
+ const Ch * res_beg = oss_.begin();
+ std::streamsize res_size = std::min(specs.truncate_, oss_.pcount());
+ int prefix_space = 0;
+ if(specs.pad_scheme_ & format_item_t::spacepad)
+ if( res_size == 0 || ( res_beg[0] !='+' && res_beg[0] !='-' ))
+ prefix_space = 1;
+ mk_str(res, res_beg, res_size, w, oss_.fill(), fl,
+ prefix_space, (specs.pad_scheme_ & format_item_t::centered) !=0 );
+ clear_buffer( oss_);
+ } // end- put_simple(..)
+
+
+
+------------------- Compiler gcc : ----------------
+
+-- Variant ** _overloads ** :
+-rwx--x--x 1 sam users 52832 2003-09-12 00:17 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_overloads/gcc/release/bench_format_overloads
+printf time :2.13
+ostream time : 2.91, = 1.3662 * printf
+parsed-once time : 4.48, = 2.10329 * printf , = 1.53952 * nullStream
+reused format time : 9.42, = 4.42254 * printf , = 3.23711 * nullStream
+format time : 11.1, = 5.21127 * printf , = 3.81443 * nullStream
+
+RERUN
+printf time :2.09
+ostream time : 2.92, = 1.39713 * printf
+parsed-once time : 4.43, = 2.11962 * printf , = 1.51712 * nullStream
+reused format time : 9.29, = 4.44498 * printf , = 3.18151 * nullStream
+format time :11.05, = 5.28708 * printf , = 3.78425 * nullStream
+
+-- Variant ** _basicfmt ** :
+-rwx--x--x 1 sam users 52832 2003-09-12 00:17 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_basicfmt/gcc/release/bench_format_basicfmt
+printf time :2.16
+ostream time : 3.01, = 1.39352 * printf
+parsed-once time : 4.41, = 2.04167 * printf , = 1.46512 * nullStream
+reused format time : 9.61, = 4.44907 * printf , = 3.19269 * nullStream
+format time :11.02, = 5.10185 * printf , = 3.66113 * nullStream
+
+-- Variant ** _no_locale ** :
+-rwx--x--x 1 sam users 52192 2003-09-12 00:09 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_no_locale/gcc/release/bench_format_no_locale
+printf time :2.1
+ostream time : 2.87, = 1.36667 * printf
+parsed-once time : 4.44, = 2.11429 * printf , = 1.54704 * nullStream
+reused format time : 8.21, = 3.90952 * printf , = 2.86063 * nullStream
+format time : 9.25, = 4.40476 * printf , = 3.223 * nullStream
+
+-- Variant ** _normal ** :
+-rwx--x--x 1 sam users 53056 2003-09-12 00:17 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_normal/gcc/release/bench_format_normal
+printf time :2.18
+ostream time : 2.92, = 1.33945 * printf
+parsed-once time : 5.75, = 2.63761 * printf , = 1.96918 * nullStream
+reused format time :10.27, = 4.71101 * printf , = 3.51712 * nullStream
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+------------------- Compiler gcc : ----------------
+
+-- Variant ** _normal ** :
+-rwx--x--x 1 sam users 49280 2003-09-10 21:12 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_normal/gcc/release/bench_format_normal
+printf time :2.16
+ostream time : 2.81, = 1.30093 * printf
+stored format time :11.56, = 5.35185 * printf , = 4.11388 * nullStream
+format time :18.69, = 8.65278 * printf , = 6.65125 * nullStream
+
+-- Variant ** _static_stream ** :
+-rwx--x--x 1 sam users 45856 2003-09-10 21:13 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_static_stream/gcc/release/bench_format_static_stream
+printf time :2.1
+ostream time : 2.79, = 1.32857 * printf
+stored format time : 4.5, = 2.14286 * printf , = 1.6129 * nullStream
+format time :10.05, = 4.78571 * printf , = 3.60215 * nullStream
+
+-- Variant ** _basicfmt ** :
+-rwx--x--x 1 sam users 47200 2003-09-10 21:13 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_basicfmt/gcc/release/bench_format_basicfmt
+printf time :2.22
+ostream time : 2.88, = 1.2973 * printf
+stored format time : 4.45, = 2.0045 * printf , = 1.54514 * nullStream
+format time :11.67, = 5.25676 * printf , = 4.05208 * nullStream
+
+
+
+
+
+The cost of imbuing locale after each object is fed :
+
+------------------- Compiler gcc : ----------------
+-- Variant _normal :
+-rwx--x--x 1 sam users 49920 2003-09-10 20:23 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_normal/gcc/release/bench_format_normal
+printf time :2.21
+ostream time : 3.1, = 1.40271 * printf
+stored format time :11.53, = 3.71935 * stream
+format time :18.86, = 6.08387 * stream
+
+-- Variant _static_stream :
+-rwx--x--x 1 sam users 43232 2003-09-10 20:24 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_static_stream/gcc/release/bench_format_static_stream
+printf time :2.19
+ostream time : 3.09, = 1.41096 * printf
+stored format time : 4.63, = 1.49838 * stream
+format time :10.12, = 3.27508 * stream
+
+-- Variant _basicfmt :
+-rwx--x--x 1 sam users 45760 2003-09-10 20:24 /home/sam/progs/Boost/bin/BBoost//libs/format/benchmark/bench_format_basicfmt/gcc/release/bench_format_basicfmt
+printf time :2.23
+ostream time : 3.14, = 1.40807 * printf
+stored format time : 4.61, = 1.46815 * stream
+format time :11.33, = 3.60828 * stream
+
+
+
+
+
+
+
+------------------- Compiler gcc : ----------------
+-- Variant _normal :
+printf time :2.15
+ostream time :4.42, = 2.05581 * printf
+stored format time :5.85, = 1.32353 * stream
+format time :11.53, = 2.6086 * stream
+-- Variant _no_reuse_stream :
+printf time :2.13
+ostream time :4.4, = 2.06573 * printf
+stored format time :11.1, = 2.52273 * stream
+format time :14.3, = 3.25 * stream
+-- Variant _stringstr :
+printf time :2.01
+ostream time :4.42, = 2.199 * printf
+stored format time :7.92, = 1.79186 * stream
+format time :12.8, = 2.89593 * stream
+
+------------------- Compiler intel-linux-7.1 : ----------------
+-- Variant _normal :
+printf time :2.08
+ostream time :4.49, = 2.15865 * printf
+stored format time :5.3, = 1.1804 * stream
+format time :17.8, = 3.96437 * stream
+-- Variant _no_reuse_stream :
+printf time :2.09
+ostream time :4.37, = 2.09091 * printf
+stored format time :10.07, = 2.30435 * stream
+format time :14.46, = 3.30892 * stream
+-- Variant _stringstr :
+printf time :1.99
+ostream time :5.16, = 2.59296 * printf
+stored format time :5.83, = 1.12984 * stream
+format time :17.42, = 3.37597 * stream
+
+
+
+
+// older Result with gcc-3.03 on linux :
+
+// With flag -g :
+
+/***
+printf time :1.2
+ostream time :2.84, = 2.36667 * printf
+stored format time :8.91, = 3.13732 * stream
+format time :15.35, = 5.40493 * stream
+format3 time :21.83, = 7.68662 * stream
+***/
+
+
+// With flag -O
+
+/***
+printf time :1.16
+ostream time :1.94, = 1.67241 * printf
+stored format time :3.68, = 1.89691 * stream
+format time :6.31, = 3.25258 * stream
+format3 time :9.04, = 4.65979 * stream
+***/
+
+// ==> that's quite acceptable.
+
+// ------------------------------------------------------------------------------