用标准c++实现string与各种类型之间的转换

string result="10000";

int n = 0;

stream << result; stream >> n;//n等于10000

int n = 12345;

stream << n;

result =stream.str();// result等于"12345"

for (int i= 1; i < 10; ++i)

{

　　strsql << "insert into test_tab values(";

　　strsql << i << ","<< (i+10) << ");";

　　 std::string str = strsql.str();// 得到string

　　 res = sqlite3_exec(pDB,str.c_str(),0,0, &errMsg);

　　std::cout << strsql.str() << std::endl; strsql.clear();

　　strsql.str("");

}

{ ostringstream oss;//创建一个流 oss< out_type convert(const in_value & t)

{ stringstream stream; stream<>result;//向result中写入值 return result; }

 using namespace std;

using namespace boost;

int main(void)

try

{

//以下是内置类型向string转换的解决方案

//lexical_cast优势明显

int ival;

char cval;

ostringstream out_string;

string str0;

string str1;

ival = 100;

cval = 'w';

out_string << ival << " " << cval;

str0 = out_string.str();

str1 = lexical_cast(ival) + lexical_cast(cval);

cout << str0 << endl; cout << str1 << endl;

//以下是string向内置类型转换的解决方案

//几乎和stringstrem相比，lexical_cast就是类型安全的，

int itmpe;

char ctmpe;

str0 = "100k";

str1 = "100h";

istringstream in_string( str0 );

in_string >> itmpe >> ctmpe;

cout << itmpe << " " << ctmpe << endl;

itmpe = lexical_cast(str1);

ctmpe = lexical_cast(str1);

system( "PAUSE" );

return 0;

} catch(bad_lexical_cast e)

{ cout << e.what() << endl; cin.get(); }