BOOST 字符串查找示例
boost 字符串查找示例
[python]
#include <string>
#include <iostream>
#include <algorithm>
#include <functional>
#include <boost/algorithm/string/case_conv.hpp>
#include <boost/algorithm/string/find.hpp>
using namespace std;
using namespace boost;
int main() www.2cto.com
{
cout << "* find example *" << endl << endl;
string str1("abc___cde___efg");
string str2("abc");
// find "cde" substring
iterator_range<string::iterator> range=find_first( str1, string("cde") );
// convert a substring to upper case
// note that iterator range can be directly passed to the algorithm
to_upper( range );
cout << "str1 with upper-cased part matching cde: " << str1 << endl;
// get a head of the string
iterator_range<string::iterator> head=find_head( str1, 3 );
cout << "head(3) of the str1: " << string( head.begin(), head.end() ) << endl;
// get the tail
head=find_tail( str2, 5 );
cout << "tail(5) of the str2: " << string( head.begin(), head.end() ) << endl;
// char processing
char text[]="hello dolly!";
iterator_range<char*> crange=find_last(text,"ll");
// transform the range ( add 1 )
transform( crange.begin(), crange.end(), crange.begin(), bind2nd( plus<char>(), 1 ) );
// uppercase the range
to_upper( crange );
cout << text << endl;
cout << endl;
return 0;
}
boost 判定函数的使用
[python]
#include <string>
#include <iostream>
#include <functional>
#include <boost/algorithm/string/predicate.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/bind.hpp>
using namespace std;
using namespace boost;
int main()
{
cout << "* predicate example *" << endl << endl;
string str1("123xxx321");
string str2("abc");
// check if str1 starts with '123'
cout << "str1 starts with \"123\": " <<
(starts_with( str1, string("123") )?"true":"false") << endl;
// check if str1 ends with '123'
cout << "str1 ends with \"123\": " <<
(ends_with( str1, string("123") )?"true":"false") << endl;
// check if str1 containes 'xxx'
cout << "str1 contains \"xxx\": " <<
(contains( str1, string("xxx") )?"true":"false") << endl;
// check if str2 equals to 'abc'
cout << "str2 equals \"abc\": " <<
(equals( str2, string("abc") )?"true":"false") << endl;
// classification functors and all predicate
if ( all(";.,", is_punct() ) )
{
cout << "\";.,\" are all punctuation characters" << endl;
}
// classification predicates can be combined
if ( all("abcxxx", is_any_of("xabc") && !is_space() ) )
{
cout << "true" << endl;
}
cout << endl;
return 0;
}
boost替换示例
[python]
#include <string>
#include <iostream>
#include <iterator>
//#include <boost/algorithm/string/replace.hpp>
//#include <boost/algorithm/string/erase.hpp>
//#include <boost/algorithm/string/case_conv.hpp>
#include <boost/algorithm/string.hpp>
//following two includes contain second-layer function.
//they are already included by first-layer header
//#include <boost/algorithm/string/replace2.hpp>
//#include <boost/algorithm/string/find2.hpp>
using namespace std;
using namespace boost;
// uppercase formatter
/*
convert an input to upper case.
note, that this formatter can be used only on std::string inputs.
*/
inline string upcase_formatter(
const iterator_range<string::const_iterator>& replace )
{
string temp(replace.begin(), replace.end());
to_upper(temp);
return temp;
}
int main()
{
cout << "* replace example *" << endl << endl;
string str1("abc___cde___efg");
// erase 6-9th characters from the string
cout << "str1 without 6th to 9th character:" <<
erase_range_copy( str1, make_iterator_range(str1.begin()+6, str1.begin()+9) ) << endl;
// replace 6-9th character with '+++'
cout << "str1 with 6th to 9th character replaced with '+++': " <<
replace_range_copy(
str1, make_iterator_range(str1.begin()+6, str1.begin()+9), "+++" ) << endl;
cout << "str1 with 'cde' replaced with 'xyz': ";
// replace first 'cde' with 'xyz'. modify the input
replace_first_copy( ostream_iterator<char>(cout), str1, "cde", "xyz" );
cout << endl;
// replace all '___'
cout << "str1 with all '___' replaced with '---': " <<
replace_all_copy( str1, "___", "---" ) << endl;
// erase all '___'
cout << "str1 without all '___': " <<
erase_all_copy( str1, "___" ) << endl;
// replace third and 5th occurrence of _ in str1
// note that nth argument is 0-based
replace_nth( str1, "_", 4, "+" );
replace_nth( str1, "_", 2, "+" );
cout << "str1 with third and 5th occurrence of _ replace: " << str1 << endl;
// custom formatter examples
string str2("abc-xxxx-abc-xxxx-abc");
// find string 'abc' ignoring the case and convert it to upper case
cout << "upcase all 'abc'(s) in the str2: " <<
find_format_all_copy(
str2,
first_finder("abc", is_iequal()),
upcase_formatter );
cout << endl;
return 0;
}