I know its simple code, How do I fix “System not declared in scope” problem? Heres my end message: C:\Documents and Settings\Nilo\My Documents\Work\Testing\main.cpp||In function ‘int main()’:| C:\Documents and Settings\Nilo\My Documents\Work\Testing\main.cpp|8|error: ‘system’ was not declared in this scope|| |=== Build finished: 1 errors, 0 warnings ===|
How well does the C++ standard library support unicode? Terribly. A quick scan through the library facilities that might provide Unicode support gives me this list: Strings library Localization library Input/output library Regular expressions library I think all but the first one provide terrible support. I’ll get back to it in more detail after a … Read more
(.25, .25) and (.75,.75) are line’s start and end point. To draw a line from (10,10) to (20,20):
If x > y, then y – x or (y + (~x + 1)) will be negative, hence the high bit will be 1, otherwise it will be 0. But we want x <= y, which is the negation of this. Even better, drop the shift operator and use a bit mask on the high … Read more
The elements in std::map are ordered (by default) by operator< applied to the key. The code you posted, with minor edits, worked for me as you expected: Prints:
To answer the first part of your question: LPCSTR is a pointer to a const string (LP means Long Pointer) LPCTSTR is a pointer to a const TCHAR string, (TCHAR being either a wide char or char depending on whether UNICODE is defined in your project) LPTSTR is a pointer to a (non-const) TCHAR string In practice when talking about these in the past, … Read more
You can use QTextCodec to convert the bytearray to a string: (1015 is UTF-16, 1014 UTF-16LE, 1013 UTF-16BE, 106 UTF-8) From your example we can see that the string “test” is encoded as “t\0 e\0 s\0 t\0 \0 \0” in your encoding, i.e. every ascii character is followed by a \0-byte, or resp. every ascii character is encoded as 2 bytes. The … Read more
You cannot return NULL (or 0) from a function that is declared to return string because there is no appropriate implicit conversion. You might want to return an empty string though or If you want to be able to distinguish between a NULL value and an empty string, then you will have to use either … Read more
list all the other cpp files after main.cpp. ie and so on. Or you can compile them all individually. You then link all the resulting “.o” files together.
You may not do that. delete must only be used on pointers returned from allocating non-array new. You did not get &b from an allocating new-expression. You could approach the problem from another direction: Since the number of objects doesn’t change, it could be much simpler to think of the state of the object changing, instead of destroying and creating … Read more