Type mismatch error when creating iterator

Question

I'm getting a type mismatch error when I try to execute an action. Here is the line that's causing problems:

 auto iterator = table.require_find(primary_key, ("Could not find entry " + std::to_string(primary_key)).cstr());

The primary key is a uint64_t.

I'm extremely confused because this exact line of code is used in an earlier helper function, and it causes no problems there. But the second time this line is used, it causes a type mismatch error. The exact output in terminal is

Error 3050003: eosio_assert_message assertion failure
Error Details:
assertion failure with message: type mismatch

Has anybody run into this problem before? I'm completely stumped by this.

Answer 1

I identified the problem - later in the function I'm trying to create a new extended asset by adding two extended assets together, and they don't have the same extended symbol.

I'm really not sure why the print statements between that line and the line in my question weren't being printed, though - that left me with the impression that the above line was where the problem was, when in fact it was somewhere else.