Boost String Algorithms Library 函数详解二 (predicate)

Table 11.3. Predicates

Algorithm name	Description	Functions
starts_with	Check if a string is a prefix of the other one	starts_with() istarts_with()
ends_with	Check if a string is a suffix of the other one	ends_with() iends_with()
contains	Check if a string is contained of the other one	contains() icontains()
equals	Check if two strings are equal	equals() iequals()
all	Check if all elements of a string satisfy the given predicate	all()

基础示例：

 1     //starts
 2     assert(starts_with("boost_python-vc71-mt-1_33.dll", "boost"));
 3     assert(!starts_with("boost_python-vc71-mt-1_33.dll", "BOOST"));
 4     assert(istarts_with("boost_python-vc71-mt-1_33.dll", "BOOST"));
 5     //ends
 6     assert(ends_with("boost_python-vc71-mt-1_33.dll", ".dll"));
 7     assert(!ends_with("boost_python-vc71-mt-1_33.dll", ".DLL"));
 8     assert(iends_with("boost_python-vc71-mt-1_33.dll", ".DLL"));
 9     //contains    
10     assert(contains("boost_python-vc71-mt-1_33.dll", "python"));
11     assert(!contains("boost_python-vc71-mt-1_33.dll", "PYTHON"));
12     assert(icontains("boost_python-vc71-mt-1_33.dll", "PYTHON"));
13     //equals
14     assert(equals("boost", "boost"));
15     assert(!equals("boost", "BOOST"));
16     assert(iequals("boost", "BOOST"));
17     //Empty string test
18     assert(starts_with("boost_python-vc71-mt-1_33.dll", ""));
19     assert(ends_with("boost_python-vc71-mt-1_33.dll", ""));
20     assert(contains("boost_python-vc71-mt-1_33.dll", ""));
21     //all
22     assert(all("\x20\t\n\r", is_space())); 
23     assert(all("\x20\t\n\r", is_classified(std::ctype_base::space)));
24     assert(all("\x20\t\n\r", is_any_of("\x20\t\n\r")));
25     assert(all("abcde", is_from_range('a','e')));
26     assert(all("abcde", is_from_range('a','z')));
27     assert(!all("abcde", is_from_range('b','c')));
28     assert(all("abc __ de", is_from_range('a','z') || is_space() || is_any_of("_")));
29     

在前面都没有详细说明is_xxxx是哪些函数，下面列出:

 1               is_space // 空格 
 2               is_alnum // 字母和数字 
 3               is_alpha // 字母 
 4               is_cntrl // 控制字符 
 5               is_digit // 数字 
 6               is_graph // 可打印字符（不含空格） 
 7               is_lower // 小写 
 8               is_print // 可打印字符（含空格） 
 9               is_punct // 标点 
10               is_upper // 大写 
11               is_xdigit // 16进制数字
12               is_any_of // 
13               is_from_range //