Thread: Object not declared in this scope

I was wondering why I got this error:

src/test.cpp: In function âint main(int, char**)â:
src/test.cpp:21: error: âExperimentâ was not declared in this scope
src/test.cpp:21: error: âexâ was not declared in this scope
src/test.cpp:21: error: expected type-specifier before âExperimentâ
src/test.cpp:21: error: expected `;' before âExperimentâ

The constructor for Experiment was declared as public

Code:

public:
	// default constructor
	Experiment( );
	// user's input constructor
	Experiment(double bias);

Post the smallest and simplest program that demonstrates the error.