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BOOST 字符串查找示例

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发表于 2017-6-2 11:07:30 | 显示全部楼层 |阅读模式
BOOST 字符串查找示例


#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()
{  
    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
#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") &amp;&amp; !is_space() ) )
    {
        cout << "true" << endl;
    }

    cout << endl;

    return 0;
}   

boost替换示例
#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>&amp; 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;
}
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