invalid operands const char* to binary 'operator+'

[SwissProgrammer]

A question from help I was getting on page https://bytes.com/topic/c/answers/974514-what-minimum-requirements-all-17-planes-unicode-c#post3829190



There is a lot on that page, so I separated this into a new question.


Previous:

    string tempString = "";
    string stringByte;
    string words;

    for (char& _char : words) {
        numToString = to_string (i);;
        stringByte = bitset<8>(_char).to_string();
// etc.

I get the following error if I do not split up the next two lines

error: invalid operands of types 'const char*' and 'const char [23]' to binary 'operator+'

With error:

tempString = "\n      [" + _char + "]=<Combined_1 PLANE 0>" + stringByte;

Without error:

                        tempString = "\n      [" + _char;
                        tempString = tempString  + "]=<Combined_1 PLANE 0>" + stringByte;

I have been trying to understand this.
What is it saying that I need to do?


Help please.

Thank you.

[dev7060]

error: invalid operands of types 'const char*' and 'const char [23]' to binary 'operator+'

The overloaded operator+ expects at least one operand to be of string type. Try this:

tempString = string("\n      [") + _char + string("]=<Combined_1 PLANE 0>") + stringByte;

[SwissProgrammer]

dev7060,

Thank you.

You said, "at least one operand" therefore I have been studying how to do this with the other parts:

_char
I found Microsoft documentation at https://www.techiedelight.com/conver...to-string-cpp/

and

stringByte
is already a string, but not quite acceptable because it filled it with

stringByte = bitset<8>(_char).to_string();

which was not accepted by the compiler as a string.
I guess that I have to re-make it a string.

(I expect that "re-make it" is not the correct wording, but I am not certain how to say that.)

Using your guidance, I have studied this (some) and now can use this:

                string a1 = "\n      [";
                string a2(1, _char);
                string a3 = "]=<Combined_1 PLANE 0>";
                string a4 = stringByte;

//                tempString = string("\n      [") + _char + string("]=<Combined_1 PLANE 0>") + stringByte;
                tempString = a1 + a2 + a3 + a4;/

Thank you.