and <code>[]int</code> must match <code>[]E</code> of the constraint,
a compiler can infer that <code>E</code> must be <code>int</code>.
Thus, for these two equations, type inference infers
</p>

<pre>
	S ➞ Slice
	E ➞ int
</pre>

<p>
Given a set of type equations, the type parameters to solve for are
the type parameters of the functions that need to be instantiated

	}
	pkg = &apiPackage{tpkg, files}

	if usePkgCache {
		pkgCache[key] = pkg
	}

	w.imported[name] = pkg
	return pkg, nil
}

// pushScope enters a new scope (walking a package, type, node, etc)
// and returns a function that will leave the scope (with sanity checking
// for mismatched pushes & pops)
func (w *Walker) pushScope(name string) (popFunc func()) {