C++常用方法之Boost
安装：
在boost官网下载相应版本的库 http://www.boost.org/，再解压到/usr/local/目录下，就能使用了，如需要编译用于发布则可编译安装.so和.a库，具体如下：
http://www.boost.org/doc/libs/1_62_0/more/getting_started/windows.html
编译：
g++ test.cpp -o test -I/usr/local/boost_1_61_0
lexical_cast进行字符串、整数/浮点数之间的字面转换：
#include
#include
#include
int main()
{
int a = boost::lexical_cast("123456");
std::cout << a << std::endl;
double b = boost::lexical_cast("123.12");
std::cout << b << std::endl;
long double c = boost::lexical_cast("123.11");
std::cout << c << std::endl;
const double d = 123.12;
std::string s = boost::lexical_cast(d);
std::cout << s << std::endl;
int i;
try{
i = boost::lexical_cast("abc");
}
catch(boost::bad_lexical_cast & e)
{
std::cout << e.what() << std::endl;
return -1;
}
std::cout << i << std::endl;
return 0;
}
123456
123.12
123.11
123.12
bad lexical cast: source type value could not be interpreted as target
progress进度条指示：
#include
#include
#include
#include
#include
int main()
{
std::vector v(100);
std::ofstream fs("test");
boost::progress_display pd(v.size());
std::vector::iterator pos;
for(pos=v.begin();pos!=v.end();++pos)
{
fs<<*pos< date_time扩展来处理时区的问题：
#include
#include
int main()
{
boost::gregorian::date d(2010, 1, 30);
std::cout << d.year() << std::endl;
std::cout << d.month() << std::endl;
std::cout << d.day() << std::endl;
std::cout << d.day_of_week() << std::endl;
std::cout << d.end_of_month() << std::endl;
}
2010
Jan
30
Sat
2010-Jan-31
scoped_ptr等智能指针避免内存泄漏：
#include
#include
#include
#include
int main()
{
boost::shared_ptr p1(new std::string("123"));
std::cout << *p1 << '\n';
boost::shared_ptr p2(p1);
p1.reset(new std::string("234"));
std::cout << *p1.get() << '\n';
std::cout << *p2.get() << '\n';
p1.reset();
std::cout << std::boolalpha << static_cast(p2) << '\n';
boost::scoped_ptr p3(new std::string("qwe"));
std::cout << *p3 << std::endl;
//boost::scoped_ptr p4(p3); // error , is privated
//p3.reset(); //delete p3
return 0;
}
123
234
123
true
qwe
format替代C里面的sprintf进行字符串化：
#include
#include
int main()
{
std::cout << boost::format("writing %1%, x=%2% : %3%-th try") % "to" % 40.23 % 50 << std::endl;
boost::format f("a=%1%, b=%2%, c=%3%, a=%1%");
f % "string" % 2 % 10.0;
std::cout << f.str() << std::endl;
}
writing to, x=40.23 : 50-th try
a=string, b=2, c=10, a=string
algorithm/string字符串算法库：
#include
#include
#include
#include
int main()
{
std::string str("readme.txt");
if(boost::ends_with(str,"txt"))
{
std::cout << boost::to_upper_copy(str) + "UPPER" << std::endl;
assert(boost::ends_with(str, "txt"));
}
boost::replace_first(str, "readme", "followme");
std::cout << str << std::endl;
std::vector v(str.begin(),str.end());
std::vector v2 = boost::to_upper_copy(boost::erase_first_copy(v, "txt"));
for(int i=0; i tokenizer用于分词的字符串处理库：
#include
#include
#include
int main(void)
{
std::string s("This is , a ,test!");
boost::tokenizer<> tok(s);
for(boost::tokenizer<>::iterator beg=tok.begin(); beg!=tok.end();++beg)
{
std::cout << *beg << " ";
}
return 0;
}
This is a test
xpressive正则表达式库，比原来的正则表达式库boost.regex要好的是不需要编译：
#include
#include
int main()
{
boost::xpressive::cregex reg = boost::xpressive::cregex::compile("a.c");
std::cout << boost::xpressive::regex_match("abc", reg) << std::endl;
std::cout << boost::xpressive::regex_match("a+c", reg) << std::endl;
std::cout << !boost::xpressive::regex_match("ac", reg) << std::endl;
std::cout << !boost::xpressive::regex_match("abd", reg) << std::endl;
return 0;
}
1
1
1
1
any一种通用的数据类型，可以将类型包装后统一放在容器中：
#include
#include
#include
#include
int main(void)
{
typedef std::vector many;
many a;
a.push_back(2);
a.push_back(std::string("test"));
for(unsigned int i=0; i < a.size(); ++i)
{
std::cout << a[i].type().name() << std::endl;
try
{
int result = boost::any_cast(a[i]);
std::cout << result << std::endl;
}
catch(boost::bad_any_cast & ex)
{
std::cout << "cast error:" << ex.what() << std::endl;
}
}
return 0;
}
i
2
NSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE
cast error:boost::bad_any_cast: failed conversion using boost::any_cast