You can't with the Arduino. I am not quite sure why, but I think it may be because it's a Modified Harvard architecture machine.

You can better achieve what you want with variadic arguments, however:

void printConcatLine(int num, ...) {
    va_list ap;
    const char *s;

    va_start(ap, num);
    for (int i = 0; i < num; i++) {
        s = va_arg(ap, const char *);
        Serial.print(s);
    }
    va_end(ap);
    Serial.println();
}

void setup() {
    Serial.begin(115200);
    printConcatLine(3, "{", "255", "}");
}

void loop() {
    
}

The first argument is the number of arguments that follow, and all the rest are string constants.

You can't with the Arduino. I am not quite sure why, but I think it may be because it's a Modified Harvard architecture machine.

You can better achieve what you want with variadic arguments, however:

void printConcatLine(int num, ...) {
    va_list ap;
    const char *s;

    va_start(ap, num);
    for (int i = 0; i < num; i++) {
        s = va_arg(ap, const char *);
        Serial.print(s);
    }
    va_end(ap);
    Serial.println();
}

void setup() {
    Serial.begin(115200);
    printConcatLine(3, "{", "255", "}");
}

void loop() {
    
}

The first argument is the number of arguments that follow, and all the rest are string constants.