what are forward declarations

[Neo]

Hi,
I am new to C++ and want to know what are forward declarations and any
site which has a good introductory explanation.

thanks in advance,
nick

 

[Jim Langston]

Hi,
I am new to C++ and want to know what are forward declarations and any
site which has a good introductory explanation.

thanks in advance,
nick

See this and others:
http://www.parashift.com/c++-faq-lite/misc-technical-issues.html#faq-39.11

Basically:
// This won't compile because SomeFunction hasn't been declared before it's
used,
// so the compiler doesn't know how it's supposed to be used.
void main()
{
SomeFunction();
}

void SomeFunction()
{
// Do Something
}

// This will compile
SomeFunction(); // This is a forward declaration
void main()
{
SomeFunction();
}

void SomeFunction()
{
// Do Something
}

 

[=?ISO-8859-1?Q?Erik_Wikstr=F6m?=]

Hi,
I am new to C++ and want to know what are forward declarations and any
site which has a good introductory explanation.

thanks in advance,
nick

Forward declarations is a way to tell the compiler that there exists a
class with a certain name, but you don't tell it what it is.

A good example and explanation from the FAQ:
http://www.parashift.com/c++-faq-lite/misc-technical-issues.html#faq-39.11

Erik Wikström