3 C++ Boost 字符,文本
十余年的石首网站建设经验，针对设计、前端、开发、售后、文案、推广等六对一服务，响应快，48小时及时工作处理。营销型网站建设的优势是能够根据用户设备显示端的尺寸不同，自动调整石首建站的显示方式，使网站能够适用不同显示终端，在浏览器中调整网站的宽度，无论在任何一种浏览器上浏览网站，都能展现优雅布局与设计，从而大程度地提升浏览体验。创新互联从事“石首网站设计”,“石首网站推广”以来，每个客户项目都认真落实执行。
目录:
字符与数值转换
Boost format函数 简单实用
Boost format 输出人员信息 小案例
Boost format 数字处理
Boost format 高级特性
Boost String 处理,大小写转换
Boost String 字符串查找
Boost String 字符串判断式
Boost String 字符串替换:
Boost String 字符串分割
Boost String trim剔除两边字符
Boost String regex正则表达式
字符与数值转换
chunli@Linux:~/boost$ cat main.cpp
#include
#include
#include
using namespace std;
int main()
{
string s("3.14e12");
double d = boost::lexical_cast(s);
printf("%f \n",d);
try
{
int i = strtol("ff",NULL,16);//C 函数 16进制转长×××
printf("%d \n",i);
//int a = boost::lexical_cast("ff");//转换失败,抛异常
int a = boost::lexical_cast("314");//OK
printf("%d \n",a);
}
catch(boost::bad_lexical_cast &e)
{
printf("%s \n",e.what());
}
string ns = boost::lexical_cast(0xfe);
cout << ns <
Boost format函数 简单实用
chunli@Linux:~/boost$ cat main.cpp
#include
#include
#include
#include
namespace MyNS_ForOutput {
using std::cout;
using std::cerr;
using std::string;
using std::endl;
using std::flush;
using boost::format;
using boost::io::group;
}
namespace MyNS_Manips {
using std::setfill;
using std::setw;
using std::hex ;
using std::dec ;
// gcc-2.95 doesnt define the next ones
// using std::showbase ;
// using std::left ;
// using std::right ;
// using std::internal ;
}
using namespace MyNS_ForOutput;
using namespace MyNS_Manips;
int main()
{
//输出Hello 占9个宽度,接着一整空格,再输出3占6个宽度.
std::cout << format("%|1$9| %|2$6|") % "Hello" % 3 << std::endl;
//参数任意排列
cout << format("%1% %2% %3% %2% %1% \n") % "o" % "oo" % "O";
//输出-23右对齐占5个宽度,输出35左对齐占5个宽度
cout << format("(x,y) = (%1$+5d,%2$-5d) \n") % -23 % 35;
cout << format("(x,y) = (%+5d,%-5d) \n") % -23 % 35;//效果同上
cout << format("(x,y) = (%|+5|,%|-5|) \n") % -23 % 35;//效果同上
cout << format("(x,y) = (%|1$+5|,%|2$-5|)\n")% -23 % 35;//效果同上
//弱类型,40.23不会因为%s而报错
cout << format("name=%s,price=%s￥,quantity=%dKG.\n") % "apple" % 4.23 % 50;
//设置C++ IO,填充,输出格式,宽度,数据
cout << format("%2% %1% %2%\n") % 919 % group(setfill('X'), hex, setw(4), 15-1) ;
//输出不同的进制
cout << format("%1$4d is : %1$#4x, %1$#4o, %1$s,\n") % 18;
cout << format("15 -> %%##%#x ") % 15 << endl;
std::string s;
s= str( format(" %d %d ") % 11 % 22 );//类似sprintf
assert( s == " 11 22 ");
cout << "assert Ok " << endl;
//format的异常,参数过多
try {
format(" %1% %1% ") % 101 % 102;
}
catch (boost::io::too_many_args& exc) {
cerr << exc.what() << "\n别担心,这是我精心设计的错误\n";
}
//format的异常,参数过少
try {
cerr << format(" %|3$| ") % 101; //必须穿3个进来
}
catch (boost::io::too_few_args& exc) {
cerr << exc.what() << "\n别担心,这是我精心设计的错误\n";
}
//忽略异常
format f(" %|3$| ");
f.exceptions(boost::io::all_error_bits ^ (boost::io::too_few_args_bit));
f % 101;
cout << "f=" << f << endl;
cerr << "\nEverything went OK, exiting. \n";
return 0;
}
chunli@Linux:~/boost$ g++ main.cpp -Wall && ./a.out
Hello 3
o oo O oo o
(x,y) = ( -23,35 )
(x,y) = ( -23,35 )
(x,y) = ( -23,35 )
(x,y) = ( -23,35 )
name=apple,price=4.23￥,quantity=50KG.
XXXe 919 XXXe
18 is : 0x12, 022, 18,
15 -> %##0xf
assert Ok
boost::too_many_args: format-string referred to fewer arguments than were passed
别担心,这是我精心设计的错误
boost::too_few_args: format-string referred to more arguments than were passed
别担心,这是我精心设计的错误
f=
Everything went OK, exiting.
chunli@Linux:~/boost$
Boost format 输出人员信息 小案例
chunli@Linux:~/boost$ cat main.cpp
#include
#include
#include "boost/format.hpp"
using namespace std;
using boost::format;
using boost::io::group;
int main()
{
//宽度为6,居中显示
cout << format("_%|=6|_") % 1 << endl;
vector names(1, "Marc-Fran is Michel"),
surname(1,"Durand"),
tel(1, "+33 (0) 123 456 789");
names.push_back("Jean");
surname.push_back("de Lattre de Tassigny");
tel.push_back("+33 (0) 987 654 321");
names.push_back("工程师");
surname.push_back("中国杭州");
tel.push_back("+86 134 2967 8754");
for(unsigned int i=0; i
Boost format 数字处理
chunli@Linux:~/boost$ cat main.cpp
#include
#include
#include "boost/format.hpp"
#if !(BOOST_WORKAROUND(__GNUC__, < 3) && defined(__STL_CONFIG_H) )
// not for broken gcc stdlib
#include
#else
// not as complete, but compatible with gcc-2.95 :
void copyfmt(ios& left, const ios& right) {
left.fill(right.fill());
left.flags(right.flags() );
left.exceptions(right.exceptions());
left.width(right.width());
left.precision(right.precision());
}
namespace boost { namespace io {
class ios_all_saver {
std::basic_ios ios_;
std::ios & target_r;
public:
ios_all_saver(std::ios& right) : ios_(0), target_r(right) {
copyfmt(ios_, right);
}
~ios_all_saver() {
copyfmt(target_r, ios_);
}
};
} } // N.S. boost::io
// define showpos and noshowpos :
class ShowPos {
public:
bool showpos_;
ShowPos(bool v) : showpos_(v) {}
};
std::ostream& operator<<(std::ostream& os, const ShowPos& x) {
if(x.showpos_)
os.setf(ios_base:: showpos);
else
os.unsetf(ios_base:: showpos);
return os;
}
ShowPos noshowpos(false);
ShowPos showpos(true);
#endif // -end gcc-2.95 workarounds
//---------------------------------------------------------------------------//
// *** an exemple of UDT : a Rational class ****
class Rational {
public:
Rational(int n, unsigned int d) : n_(n), d_(d) {}
Rational(int n, int d); // convert denominator to unsigned
friend std::ostream& operator<<(std::ostream&, const Rational&);
private:
int n_; // numerator
unsigned int d_; // denominator
};
Rational::Rational(int n, int d) : n_(n)
{
if(d < 0) { n_ = -n_; d=-d; } // make the denominator always non-negative.
d_ = static_cast(d);
}
std::ostream& operator<<(std::ostream& os, const Rational& r) {
using namespace std;
streamsize n, s1, s2, s3;
streamsize w = os.width(0); // width has to be zeroed before saving state.
// boost::io::ios_all_saver bia_saver (os);
boost::io::basic_oaltstringstream oss;
oss.copyfmt(os );
oss << r.n_;
s1 = oss.size();
oss << "/" << noshowpos; // a rational number needs only one sign !
s2 = oss.size();
oss << r.d_ ;
s3 = oss.size();
n = w - s3;
if(n <= 0) {
os.write(oss.begin(), oss.size());
}
else if(os.flags() & std::ios_base::internal) {
std::streamsize n1 = w/2, n2 = w - n1, t;
t = (s3-s1) - n2; // is 2d part '/nnn' bigger than 1/2 w ?
if(t > 0) {
n1 = w -(s3-s1); // put all paddings on first part.
n2 = 0; // minimal width (s3-s2)
}
else {
n2 -= s2-s1; // adjust for '/', n2 is still w/2.
}
os << setw(n1) << r.n_ << "/" << noshowpos << setw(n2) << r.d_;
}
else {
if(! (os.flags() & std::ios_base::left)) {
// -> right align. (right bit is set, or no bit is set)
os << string(n, ' ');
}
os.write(oss.begin(), s3);
if( os.flags() & std::ios_base::left ) {
os << string(n, ' ');
}
}
return os;
}
int main(){
using namespace std;
using boost::format;
using boost::io::group;
using boost::io::str;
string s;
Rational r(16, 9);
cout << "start ! " << endl;
cout << r << endl; // "16/9"
cout << showpos << r << ", " << 5 << endl; // "+16/9, +5"
cout << format("%02d : [%0+9d] \n") % 1 % r ; // "01 : [+016 / 0009]"
cout << format("%02d : [%_+9d] \n") % 2 % Rational(9,160);
// "02 : [+9 / 160]"
cout << format("%02d : [%_+9d] \n") % 3 % r;
// "03 : [+16 / 9]"
cout << format("%02d : [%_9d] \n") % 4 % Rational(8,1234);
// "04 : [8 / 1234]"
cout << format("%02d : [%_9d] \n") % 5 % Rational(1234,8);
// "05 : [1234 / 8]"
cout << format("%02d : [%09d] \n") % 6 % Rational(8,1234);
// "06 : [0008 / 1234]"
cout << format("%02d : [%0+9d] \n") % 7 % Rational(1234,8);
// "07 : [+1234 / 008]"
cout << format("%02d : [%0+9d] \n") % 8 % Rational(7,12345);
// "08 : [+07 / 12345]"
cerr << "\n\nEverything went OK, exiting. \n";
return 0;
}
chunli@Linux:~/boost$ g++ main.cpp -Wall && ./a.out
start !
16/9
+16/9, +5
01 : [+016/0009]
02 : [+ 9/ 160]
03 : [+ 16/ 9]
04 : [ 8/1234]
05 : [1234/ 8]
06 : [0008/1234]
07 : [+1234/008]
08 : [+07/12345]
Everything went OK, exiting.
chunli@Linux:~/boost$
Boost format 高级特性
chunli@Linux:~/boost$ cat main.cpp
#include
#include
#include "boost/format.hpp"
namespace MyNS_ForOutput {
using std::cout; using std::cerr;
using std::string;
using std::endl; using std::flush;
using boost::format;
using boost::io::group;
}
namespace MyNS_Manips {
using std::setfill;
using std::setw;
using std::hex ;
using std::dec ;
using std::showbase ;
using std::left ;
using std::right ;
using std::internal ;
}
int main(){
using namespace MyNS_ForOutput;
using namespace MyNS_Manips;
std::string s;
//------------------------------------------------------------------------
// storing the parsed format-string in a 'formatter' :
// format objects are regular objects that can be copied, assigned,
// fed arguments, dumped to a stream, re-fed arguments, etc...
// So users can use them the way they like.
format fmter("%1% %2% %3% %1% \n");
fmter % 10 % 20 % 30;
cout << fmter;
// prints "10 20 30 10 \n"
// note that once the fmter got all its arguments,
// the formatted string stays available (until next call to '%')
// The result is available via function str() or stream's << :
cout << fmter;
// prints the same string again.
// once you call operator% again, arguments are cleared inside the object
// and it is an error to ask for the conversion string before feeding all arguments :
fmter % 1001;
try { cout << fmter; }
catch (boost::io::too_few_args& exc) {
cout << exc.what() << "\n\t\t***Dont worry, that was planned\n";
}
// we just need to feed the last two arguments, and it will be ready for output again :
cout << fmter % 1002 % 1003;
// prints "1001 1002 1003 1001 \n"
cout << fmter % 10 % 1 % 2;
// prints "10 1 2 10 \n"
//---------------------------------------------------------------
// using format objects
// modify the formatting options for a given directive :
fmter = format("%1% %2% %3% %2% %1% \n");
fmter.modify_item(4, group(setfill('_'), hex, showbase, setw(5)) );// 这点可以深入看看
cout << fmter % 1 % 2 % 3;
// prints "1 2 3 __0x2 1 \n"
// bind one of the argumets :
fmter.bind_arg(1, 18);// 这点可以深入看看
cout << fmter % group(hex, showbase, 20) % 30; // %2 is 20, and 20 == 0x14
// prints "18 0x14 30 _0x14 18 \n"
fmter.modify_item(4, setw(0)); // cancels previous width-5
fmter.bind_arg(1, 77); // replace 18 with 77 for first argument.
cout << fmter % 10 % 20;
// prints "77 10 20 0xa 77 \n"
try
{
cout << fmter % 6 % 7 % 8; // Aye ! too many args, because arg1 is bound already
}
catch (boost::io::too_many_args& exc)
{
cout << exc.what() << "\n\t\t***Dont worry, that was planned\n";
}
// clear regular arguments, but not bound arguments :
fmter.clear();
cout << fmter % 2 % 3;
// prints "77 2 3 0x2 77 \n"
// clear_binds() clears both regular AND bound arguments :
fmter.clear_binds();
cout << fmter % 1 % 2 % 3;
// prints "1 2 3 0x2 1 \n"
// setting desired exceptions :
fmter.exceptions( boost::io::all_error_bits ^( boost::io::too_many_args_bit ) );
cout << fmter % 1 % 2 % 3 % 4 % 5 % 6 ;
// -----------------------------------------------------------
// misc:
// unsupported printf directives %n and asterisk-fields are purely ignored.
// do *NOT* provide an argument for them, it is an error.
cout << format("|%5d| %n") % 7 << endl;
// prints "| 7| "
cout << format("|%*.*d|") % 7 << endl;
// prints "|7|"
// truncations of strings :
cout << format("%|.2s| %|8c|.\n") % "root" % "user";
// prints "ro u.\n"
// manipulators conflicting with format-string : manipulators win.
cout << format("%2s") % group(setfill('0'), setw(6), 1) << endl;
// prints "000001"
cout << format("%2$5s %1% %2$3s\n") % 1 % group(setfill('X'), setw(4), 2) ;
// prints "XXX2 1 XXX2\n"
// width is 4, as set by manip, not the format-string.
// nesting :
cout << format("%2$014x [%1%] %2$05s\n") % (format("%05s / %s") % -18 % 7)
% group(showbase, -100);
// prints "0x0000ffffff9c [-0018 / 7] -0100\n"
cout << "\n\nEverything went OK, exiting. \n";
return 0;
}
chunli@Linux:~/boost$ g++ main.cpp -Wall && ./a.out
10 20 30 10
10 20 30 10
boost::too_few_args: format-string referred to more arguments than were passed
***Dont worry, that was planned
1001 1002 1003 1001
10 1 2 10
1 2 3 __0x2 1
18 0x14 30 _0x14 18
77 10 20 0xa 77
boost::too_many_args: format-string referred to fewer arguments than were passed
***Dont worry, that was planned
77 2 3 0x2 77
1 2 3 0x2 1
1 2 3 0x2 1
| 7|
|7|
ro u.
000001
XXX2 1 XXX2
0x0000ffffff9c [-0018 / 7] -0100
Everything went OK, exiting.
chunli@Linux:~/boost$
Boost String 处理,大小写转换
chunli@Linux:~/workspace/Boost$ cat str.cpp
/*
* str.cpp
*
* Created on: 2016年12月2日
* Author: chunli
*/
#include
#include
#include
#include
#include
using namespace std;
using namespace boost;
int main()
{
string str1("AbCdEfG");
vector vec1( str1.begin(), str1.end() );
cout << "转换为小写";
to_lower_copy( ostream_iterator(cout), vec1 );//把结构拷贝到IO流
cout << endl;
copy(vec1.begin(),vec1.end(),ostream_iterator(cout));//看看数组里面装的是什么
cout << endl;
to_lower(vec1 );
//cout << vec1 << endl;
cout << "转换为大写" << to_upper_copy( str1 ) << endl;//
to_lower( str1 );
cout << "转换为小写" << str1 << endl;
return 0;
}
chunli@Linux:~/workspace/Boost$ g++ str.cpp -Wall && ./a.out
转换为小写abcdefg
AbCdEfG
转换为大写ABCDEFG
转换为小写abcdefg
chunli@Linux:~/workspace/Boost$
Boost String 字符串查找
chunli@Linux:~/workspace/Boost$ cat main.cpp
#include
#include
#include
#include
#include
#include
using namespace std;
using namespace boost;
int main()
{
string str1("abc___cde___efg");
string str2("abc");
//查找"cde",iterator_range 记录的是两个迭代器的位置
iterator_range range=find_first( str1, string("cde") );
//range 记录的是两个迭代器位置,to_upper开始转换
to_upper( range );
cout << "查找cde,并转换 " << str1 << endl;
//查找前3个字符
iterator_range head=find_head( str1, 3 );
cout << "head(3) of the str1: " << string( head.begin(), head.end() ) << endl;
//查找尾部几个字符,有容错功能
head=find_tail( str2, 5 );
cout << "tail(5) of the str2: " << string( head.begin(), head.end() ) << endl;
char text[]="hello dolly!";
iterator_range crange=find_last(text,"ll");//crange记录最后的ll的位置
transform( crange.begin(), crange.end(), crange.begin(), bind2nd( plus(), 2 ) );//ll加2就是nn
to_upper( crange ); //crange记录最后的ll的位置
cout << text << endl;
return 0;
}
chunli@Linux:~/workspace/Boost$ g++ main.cpp -Wall && ./a.out
查找cde,并转换 abc___CDE___efg
head(3) of the str1: abc
tail(5) of the str2: abc
hello doNNy!
chunli@Linux:~/workspace/Boost$
Boost String 字符串判断式
chunli@Linux:~/workspace/Boost$ cat main.cpp
#include
#include
#include
#include
#include
#include
using namespace std;
using namespace boost;
int main()
{
string str1("123xxx321");
string str2("abc");
// 判断字符串的开头
cout << "str1 starts with \"123\": " << (starts_with( str1, string("123") )?"true":"false") << endl;
// 判断字符串的结尾
cout << "str1 ends with \"123\": " << (ends_with( str1, string("123") )?"true":"false") << endl;
// 判断是否存在子串
cout << "str1 contains \"xxx\": " << (contains( str1, string("xxx") )?"true":"false") << endl;
// 检测两个字符串是否相等
cout << "str2 equals \"abc\": " << (equals( str2, string("abc") )?"true":"false") << endl;
// 检测all里面所有的是不是 符号
if ( all(";.,", is_punct() ) )
{
cout << "\";.,\" are all punctuation characters" << endl;
}
// 检查str1每个字符 是不是属于 str2中
if ( all("abcxxx", is_any_of("xabc") && !is_space() ) )
{
cout << "true" << endl;
}
return 0;
}
chunli@Linux:~/workspace/Boost$ g++ main.cpp -Wall && ./a.out
str1 starts with "123": true
str1 ends with "123": false
str1 contains "xxx": true
str2 equals "abc": true
";.," are all punctuation characters
true
chunli@Linux:~/workspace/Boost$
Boost String 字符串替换
chunli@Linux:~/workspace/Boost$ cat main.cpp
#include
#include
#include
#include
using namespace std;
using namespace boost;
inline string upcase_formatter( const iterator_range& Replace )
{
string Temp(Replace.begin(), Replace.end());
to_upper(Temp);
return Temp;
}
int main()
{
string str1("abc___cde___efg");
//删除从6到9的字符,不影响str1
cout << erase_range_copy( str1, make_iterator_range(str1.begin()+6, str1.begin()+9) ) << endl;
// 从6到9的字符,换成+++,只能处理3位
cout <(cout), str1, "cde", "中国杭州" );
cout << endl;
// 全部替换,不影响str1
cout << replace_all_copy( str1, "___", "--" ) << endl;
cout << replace_all_copy( str1, "___", "----" ) << endl;
// 全部删除,不影响str1
cout << erase_all_copy( str1, "___" ) << endl;
// 修改第N个字符,影响str1
replace_nth( str1, "_", 4, "+" );
replace_nth( str1, "_", 2, "+" );
cout << str1 << endl;
//忽略大小写转换
string str2("abC-xxxx-AbC-xxxx-abc");
cout << find_format_all_copy( str2,first_finder("abc", is_iequal()), upcase_formatter ) << endl;
return 0;
}
chunli@Linux:~/workspace/Boost$ g++ main.cpp -Wall && ./a.out
abc______efg
abc___+++___efg
abc___中国杭州___efg
abc--cde--efg
abc----cde----efg
abccdeefg
abc__+cde_+_efg
ABC-xxxx-ABC-xxxx-ABC
chunli@Linux:~/workspace/Boost$
Boost String 字符串分割
chunli@Linux:~/workspace/Boost$ cat main.cpp
#include
#include
#include
#include
#include
#include
#include
#include
using namespace std;
using namespace boost;
int main()
{
string str1("abc-*-ABC-*-aBc");
cout << "Before: " << str1 << endl;
//忽略大小写查找abc,并打印出来
typedef find_iterator string_find_iterator;
string_find_iterator It = make_find_iterator(str1, first_finder("abc", is_iequal()));
for(;It != string_find_iterator();++It)
{
cout << copy_range(*It) << endl;
transform(It->begin(), It->end(), It->begin(), bind2nd( plus(), 1 ) );//每个字符加1
}
cout << "After: " << str1 << endl;
//以 -* 任意字符为分隔符
vector ResultCopy;
split(ResultCopy, str1, is_any_of("-*"), token_compress_on);
for(unsigned int nIndex=0; nIndex
Boost String trim剔除两边字符
chunli@Linux:~/workspace/Boost$ cat main.cpp
#include
#include
#include
#include
using namespace std;
using namespace boost;
int main()
{
string str1(" 1x x x x1 ");
// 去除左边的空格
cout <<"-" << trim_left_copy( str1 ) << "-"<< endl;
// 去除右边的空格,直接修改对象
trim_right( str1 );
cout << "-" << str1 << "-" << endl;
//去除两边 含< >的任意字符
string str2("<> tr <> im <>");
cout << "-"<< trim_copy_if( str2, is_any_of("< >") ) << "-" << endl;
//去除两边包含的任意数字字符
string str3("123abs343");
cout << "-" << trim_copy_if( str3, is_digit() ) << "-" << endl;
return 0;
}
chunli@Linux:~/workspace/Boost$ g++ main.cpp -Wall && ./a.out
-1x x x x1 -
- 1x x x x1-
-tr <> im-
-abs-
chunli@Linux:~/workspace/Boost$
Boost String regex正则表达式
chunli@Linux:~/workspace/Boost$ cat main.cpp
#include
#include
#include
#include
#include
using namespace std;
using namespace boost;
int main()
{
string str1("abc__(456)__123__(123)__cde");
//匹配 (多个数字) 这样的格式
cout << replace_all_regex_copy( str1, regex("\\(([0-9]+)\\)"), string("-$1-") ) << endl;
cout << replace_all_regex_copy( str1, regex("\\(([0-9]+)\\)"), string("前$1后") ) << endl;
//删除所有的字母
cout << erase_all_regex_copy( str1, regex("[[:alpha:]]+") ) << endl;
// /匹配 (多个数字) 这样的格式
replace_all_regex( str1, regex("_(\\([^\\)]*\\))_"), string("-$1-") );
cout << str1 << endl;
return 0;
}
chunli@Linux:~/workspace/Boost$ g++ main.cpp -l boost_regex -Wall && ./a.out
abc__-456-__123__-123-__cde
abc__前456后__123__前123后__cde
__(456)__123__(123)__
abc_-(456)-_123_-(123)-_cde
chunli@Linux:~/workspace/Boost$
网页名称：3C++Boost字符,文本
标题路径：http://cdweb.net/article/ghdihd.html
