boost之string_algo
string_algo是用于处理字符串查找，替换，转换等一系列的字符串算法
前缀i:表示大小写不敏感
后缀_copy:表示不变动输入,返回处理结果的拷贝
后缀_if:表示算法需要一个判断式的谓词函数对象。
#include <iostream>
#include <vector>
#include <string>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
int main()
{
string str("readme.txt");
if (ends_with(str,"txt"))//判断后缀
{
cout << to_upper_copy(str) + " UPPER" <<endl;//大写
}
replace_first(str,"readme","followme");//替换
cout << str <<endl;
vector<char> v(str.begin(),str.end());
vector<char> v2 = to_upper_copy(erase_first_copy(v,"txt"));
for (int i = 0;i < v2.size();++i)
{
cout << v2[i];
}
return 0;
}
1.大小写转换，如上。
2.判断式
2.1判断式(算法)，用于子串的匹配
starts_with
ends_with
contains
equals
lexicographcical_compare
#include <iostream>
#include <vector>
#include <string>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
int main()
{
string str("Power Bomb");
if (iends_with(str,"bomb"))
{
cout << "success iends_with" <<endl;
}
if (ends_with(str,"bomb"))
{
cout << "success ends_with" <<endl;
}
if (contains(str,"er"))
{
cout << "success contains" <<endl;
}
return 0;
}
2.2.判断式（函数对象）用于字符串之间的比较
#include <iostream>
#include <vector>
#include <string>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
int main()
{
string str1("Samus");
string str2("samus");
if (is_equal()(str1,str2))
{
cout << "is equal" <<endl;
}
if (is_less()(str1,str2))
{
cout << "is less" <<endl;
}
return 0;
}
2.3.分类（返回函数对象）用于分类
is_space判断字符是否为空格
is_alnum判断是否为字符或者数字
3.修剪
trim_left,trim_right,trim删除左右两端的空格，使用谓词判断if
#include <iostream>
#include <vector>
#include <string>
#include <boost/format.hpp>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
int main()
{
format fmt("%s\n");
string str = " samus aran";
cout << fmt % trim_copy(str);
cout << fmt % trim_left_copy(str);
trim_right(str);
cout << fmt % str;
string str2 = "2013 Happy lin Year!";
cout << fmt % trim_left_copy_if(str2,is_digit());
cout << fmt % trim_right_copy_if(str2,is_punct());
return 0;
}
4. 查找
find_first 查找字符串第一次出现的位置
find_last 查找字符串最后一次出现的位置
#include <iostream>
#include <vector>
#include <string>
#include <boost/format.hpp>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
int main()
{
format fmt("%s\n.pos=%d\n");
string str = "Long long ago,there was a king.";
iterator_range<string::iterator> rge;
rge = find_first(str,"long");
cout << fmt % rge % (rge.begin()-str.begin());
return 0;
}
5.替换和删除与查找类似
#include <iostream>
#include <vector>
#include <string>
#include <boost/format.hpp>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
int main()
{
string str = "Samus beat the monster.\n";
cout << replace_first_copy(str,"Samus","samus");
replace_first(str,"beat","kill");
cout <<str;
return 0;
}
6.分割
#include <iostream>
#include <vector>
#include <string>
#include <deque>
#include <list>
#include <boost/format.hpp>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
int main()
{
string str = "Smaus,Link.Zelda::Mario_Luigi+zelda";
deque<string> d;
ifind_all(d,str,"zELDA");
if (d.size())
{
cout << "split right" <<endl;
}
list<string> l;
split(l,str,is_any_of(",.:_+"));
for (list<string>::iterator it = l.begin();it != l.end();++it)
{
cout << *it <<endl;
}
return 0;
}
7.合并
#include <iostream>
#include <vector>
#include <string>
#include <boost/assign.hpp>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost;
using namespace boost::assign;
int main()
{
vector<string> v = list_of("liuwei")("linlin")("ceshi");
cout << join(v,"+")<<endl;
struct is_contains_i
{
bool operator()(const string &x)
{
return contains(x,"i");
}
};
cout << join_if(v,"****",is_contains_i());
return 0;
}