Update README.

Adds a TaggedUnion example and adds a section for supported compiler versions.

README.md

@@ -1,13 +1,81 @@
 TaggedAlgebraic
 ===============
 
-Implementation of a generic algebraic data type with a tagged union storage. All operations of the contained types are available for the `TaggedAlgebraic`
+Implementation of a generic `TaggedUnion` type along with a `TaggedAlgebraic` type that forwards all methods and operators of the contained types using dynamic dispatch.
 
 [![Build Status](https://travis-ci.org/s-ludwig/taggedalgebraic.svg?branch=master)](https://travis-ci.org/s-ludwig/taggedalgebraic) [![codecov](https://codecov.io/gh/s-ludwig/taggedalgebraic/branch/master/graph/badge.svg)](https://codecov.io/gh/s-ludwig/taggedalgebraic)
 
 
-Usage
------
+Usage of `TaggedUnion`
+----------------------
+
+```d
+import taggedalgebraic;
+
+struct Foo {
+	string name;
+	void bar() {}
+}
+
+union Base {
+	int count;
+	int offset;
+	string str;
+	Foo foo;
+}
+
+alias TUnion = TaggedUnion!Base;
+
+// Instantiate
+TUnion taggedInt = TUnion.count(5);
+TUnion taggedString = TUnion.str("Hello");
+TUnion taggedFoo = TUnion.foo;
+TUnion taggedAny = taggedInt;
+taggedAny = taggedString;
+taggedAny = taggedFoo;
+
+// Default initializes to the first field
+TUnion taggedDef;
+assert(taggedDef.isCount);
+assert(taggedDef.getCount == int.init);
+
+// Check type: TUnion.Kind is an enum
+assert(taggedInt.kind == TUnion.Kind.count);
+assert(taggedString.kind == TUnion.Kind.str);
+assert(taggedFoo.kind == TUnion.Kind.foo);
+assert(taggedAny.kind == TUnion.Kind.foo);
+
+// A shorter syntax is also available
+assert(taggedInt.isCount);
+assert(!taggedInt.isOffset);
+assert(taggedString.isStr);
+assert(taggedFoo.isFoo);
+assert(taggedAny.isFoo);
+
+// Set to a different type
+taggedAny.setStr("bar");
+assert(taggedAny.isStr);
+assert(taggedAny.getStr() == "bar");
+
+// Modify contained value by reference
+taggedAny.getStr() = "baz";
+assert(taggedAny.getStr() == "baz");
+
+// In addition to the getter, the contained value can be extracted using get!()
+// or by casting
+assert(taggedInt.get!(TUnion.Kind.count) == 5);
+assert(taggedInt.get!int == 5);
+assert(cast(byte)taggedInt == 5);
+
+// Multiple kinds of the same type are supported
+taggedAny.setOffset(5);
+assert(taggedAny.isOffset);
+assert(taggedAny.isCount);
+```
+
+
+Usage of `TaggedAlgebraic`
+--------------------------
 
 ```d
 import taggedalgebraic;
@@ -23,27 +91,27 @@ union Base {
 	Foo foo;
 }
 
-alias Tagged = TaggedAlgebraic!Base;
+alias TAlgebraic = TaggedAlgebraic!Base;
 
 // Instantiate
-Tagged taggedInt = 5;
-Tagged taggedString = "Hello";
-Tagged taggedFoo = Foo();
-Tagged taggedAny = taggedInt;
+TAlgebraic taggedInt = 5;
+TAlgebraic taggedString = "Hello";
+TAlgebraic taggedFoo = Foo();
+TAlgebraic taggedAny = taggedInt;
 taggedAny = taggedString;
 taggedAny = taggedFoo;
 
-// Check type: Tagged.Kind is an enum
-assert(taggedInt.kind == Tagged.Kind.i);
-assert(taggedString.kind == Tagged.Kind.str);
-assert(taggedFoo.kind == Tagged.Kind.foo);
-assert(taggedAny.kind == Tagged.Kind.foo);
+// Check type: TAlgebraic.Kind is an enum
+assert(taggedInt.kind == TAlgebraic.Kind.i);
+assert(taggedString.kind == TAlgebraic.Kind.str);
+assert(taggedFoo.kind == TAlgebraic.Kind.foo);
+assert(taggedAny.kind == TAlgebraic.Kind.foo);
 
 // In most cases, can simply use as-is
 auto num = 4 + taggedInt;
 auto msg = taggedString ~ " World!";
 taggedFoo.bar();
-if (taggedAny.kind == Tagged.Kind.foo) // Make sure to check type first!
+if (taggedAny.kind == TAlgebraic.Kind.foo) // Make sure to check type first!
 	taggedAny.bar();
 //taggedString.bar(); // AssertError: Not a Foo!
 
@@ -51,22 +119,30 @@ if (taggedAny.kind == Tagged.Kind.foo) // Make sure to check type first!
 auto i   = cast(int)    taggedInt;
 auto str = cast(string) taggedString;
 auto foo = cast(Foo)    taggedFoo;
-if (taggedAny.kind == Tagged.Kind.foo) // Make sure to check type first!
+if (taggedAny.kind == TAlgebraic.Kind.foo) // Make sure to check type first!
 	auto foo2 = cast(Foo) taggedAny;
 //cast(Foo) taggedString; // AssertError!
 
 // Kind is an enum, so final switch is supported:
 final switch (taggedAny.kind) {
-	case Tagged.Kind.i:
+	case TAlgebraic.Kind.i:
 		// It's "int i"
 		break;
 
-	case Tagged.Kind.str:
+	case TAlgebraic.Kind.str:
 		// It's "string str"
 		break;
 
-	case Tagged.Kind.foo:
+	case TAlgebraic.Kind.foo:
 		// It's "Foo foo"
 		break;
 }
 ```
+
+Compiler support
+----------------
+
+The library is tested to work on the following compilers:
+
+- DMD 2.076.1 up to 2.084.1
+- LDC 1.6.0 up to 1.14.0