对于微调，使用boost字符串算法:

#include <boost/algorithm/string.hpp>

using namespace std;
using namespace boost;

// ...

string str1(" hello world! ");
trim(str1);      // str1 == "hello world!"

你可以使用这个解决方案来删除一个字符:

#include <algorithm>
#include <string>
using namespace std;

str.erase(remove(str.begin(), str.end(), char_to_remove), str.end());

删除所有空白字符，如制表符和换行符(c++ 11):

string str = " \n AB cd \t efg\v\n";
str = regex_replace(str,regex("\\s"),"");

你能使用Boost String算法吗?http://www.boost.org/doc/libs/1_35_0/doc/html/string_algo/usage.html#id1290573

erase_all(str, " "); 

只是为了好玩，因为其他答案比这个好得多。

#include <boost/hana/functional/partial.hpp>
#include <iostream>
#include <range/v3/range/conversion.hpp>
#include <range/v3/view/filter.hpp>
int main() {
    using ranges::to;
    using ranges::views::filter;
    using boost::hana::partial;
    auto const& not_space = partial(std::not_equal_to<>{}, ' ');
    auto const& to_string = to<std::string>;

    std::string input = "2C F4 32 3C B9 DE";
    std::string output = input | filter(not_space) | to_string;
    assert(output == "2CF4323CB9DE");
}

std::string::iterator end_pos = std::remove(str.begin(), str.end(), ' ');
str.erase(end_pos, str.end());