Provides an implicit conversion that adds can methods to String to support the syntax of FlatSpec, WordSpec, org.scalatest.fixture.FlatSpec, and fixture.WordSpec.

For example, this trait enables syntax such as the following test registration in FlatSpec and fixture.FlatSpec:

"A Stack (when empty)" can "be empty" in { ... }
                       ^

It also enables syntax such as the following shared test registration in FlatSpec and fixture.FlatSpec:

"A Stack (with one item)" can behave like nonEmptyStack(stackWithOneItem, lastValuePushed)
                          ^

In addition, it supports the registration of subject descriptions in WordSpec and fixture.WordSpec, such as:

"A Stack (when empty)" can { ...
                       ^

And finally, it also supportds the registration of subject descriptions with after words in WordSpec and fixture.WordSpec. For example:

def provide = afterWord("provide")

"The ScalaTest Matchers DSL" can provide {
                             ^

The reason this implicit conversion is provided in a separate trait, instead of being provided directly in FlatSpec, WordSpec, fixture.FlatSpec, and fixture.WordSpec, is primarily for design symmetry with ShouldVerb and MustVerb. Both ShouldVerb and MustVerb must exist as a separate trait because an implicit conversion provided directly would conflict with the implicit conversion that provides should or must methods on String in the Matchers and MustMatchers traits.