# EAPI 1

## IUSE defaults

A + or - prefix added to the beginning of a flag in IUSE creates a default USE setting that respectively enables or disables the corresponding USE flag.

## Phases

### Default src_compile Phase Function

Support for the ECONF_SOURCE variable, which is also supported by econf, has been added to the default src_compile implementation.

    src_compile() {
    	if [[ -x ${ECONF_SOURCE:-.}/configure ]] ; then
    		econf
    	fi
    	if [ -f Makefile ] || [ -f GNUmakefile ] || [ -f makefile ] ; then
    		emake || die "emake failed"
    	fi
    }

## SLOT Dependencies

Any valid atom can be constrained to match a specific SLOT. This is accomplished by appending a colon to the atom, followed by a SLOT value.

## Slot Dependency Examples

Atom
x11-libs/qt:3
~x11-libs/qt-3.3.8:3
>=x11-libs/qt-3.3.8:3
=x11-libs/qt-3.3*:3