GNU C++ Compiler
	Debugging: Compiler Errors

compilation of header file requested

You can't compile a header file--at least not with the .h extension! If you really want to compile this, either write a test program that includes your library or temporarily rename your library .cpp (but don't forget to change the name back when you're done).

no such file or directory

Check your spelling! Also, don't forget that if this is a standard library (part of the C++ standard), you type #include <library.h>, but if this is a library you wrote, #include "library.h". If it's a library I've made available to you, make sure you include the full name to my directory:
#include "/homes/csg/1995/ordonez/cosc161/library.h"

no match for `operator <<(...) / >>(...)'

You're trying to cout/cin something that isn't a standard type (you may have placed a function name where you really meant to have a function call).

parse error before `?'

This is the compiler's "general-purpose" error. Check the following:

• semicolons at the end of:
  • the previous line of code--if it's the end of a statement, it should have a semicolon, otherwise it shouldn't!
  • function headers in definitions--often cause this problem (remember, the prototype needs a semicolon, the definition can't have one). Rule of thumb: if it has a block (enclosed in braces) after it, it shouldn't have a semicolon!
  • cout statements that continue on the next line.
• braces and parentheses--match them up or this error will show up all over the place!
• cin/cout--make sure there are "arrows" (<< or >>) between every 2 items
• spelling--especially keywords!

type specifier omitted for parameter

In a function prototype or definition, every parameter (or argument) must have a type before it (you can't have a function prototype like this: int sum(int x, y); even if they're both integers. You must enter int sum(int x, int y);!

syntax error before `?')

This is often the result of leaving out the empty parentheses after the name of a function that doesn't take parameters. Remember that void main, for example, always needs the empty parentheses after it, even if it doesn't take arguments. It's the compiler's way of keeping function names and variable names separate.

undeclared (first use this function)

Make sure you've declared all your variables (at the top of the function. Also check that you've spelled all names the same way everywhere--both the declaration and every use of a variable (remember that case matters).
If this error shows up in reference to a "language-standard" object such as cout, cin, endl, etc., make sure you're including all the right libraries!

undefined or invalid # directive

Check #include, #define, etc. for misspellings.

unterminated string or character constant / possible real start of unterminated constant

You forgot to close the double quotes at the end of a string. It may even start on a different line than where the error shows up.

wrong type argument to unary minus

You can't use dashes (minus signs) in names (function names or variable names). Check also for a misplaced dash elsewhere (just outside a string, etc.)!

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