Case-insensitive string comparison in C++ [closed]

Answer 1

Short and nice. No other dependencies, than extended std C lib.

strcasecmp(str1.c_str(), str2.c_str()) == 0

returns true if str1 and str2 are equal. strcasecmp may not exist, there could be analogs stricmp, strcmpi, etc.

Example code:

#include 
#include 
#include  //For strcasecmp(). Also could be found in 

using namespace std;

/// Simple wrapper
inline bool str_ignoreCase_cmp(std::string const& s1, std::string const& s2) {
    if(s1.length() != s2.length())
        return false;  // optimization since std::string holds length in variable.
    return strcasecmp(s1.c_str(), s2.c_str()) == 0;
}

/// Function object - comparator
struct StringCaseInsensetiveCompare {
    bool operator()(std::string const& s1, std::string const& s2) {
        if(s1.length() != s2.length())
            return false;  // optimization since std::string holds length in variable.
        return strcasecmp(s1.c_str(), s2.c_str()) == 0;
    }
    bool operator()(const char *s1, const char * s2){ 
        return strcasecmp(s1,s2)==0;
    }
};


/// Convert bool to string
inline char const* bool2str(bool b){ return b?"true":"false"; }

int main()
{
    cout<< bool2str(strcasecmp("asd","AsD")==0) <

Output:

true
true
true
true
true