Convert NSString to icu::UnicodeString back and forth

NSString+UnicodeString.mm

//
//  NSString+UnicodeString.m
//
//  Created by Johan Hernandez on 1/18/15.
//  Copyright (c) 2015 Bithavoc.io - All rights reserved.
//

#import "NSString+UnicodeString.hh"
#include <string>

@implementation NSString (UnicodeString)

+ (NSString*)stringWithUnicodeString:(const icu::UnicodeString&) ustr {
    std::string str;
    ustr.toUTF8String(str);
    return [NSString stringWithUTF8String:str.c_str()];
}

+ (NSString*)stringWithStdString:(const std::string&) str {
    return [NSString stringWithUTF8String:str.c_str()];
}

- (icu::UnicodeString) UnicodeString {
    return icu::UnicodeString(self.UTF8String);
}

@end