documented new C++ support

doc/idetools.txt

@@ -421,7 +421,7 @@ returned by idetools returns also the pragmas for the proc.
 | **Docstring**: docstring if available.
 
 .. code-block:: nim
-    Open(filename, fmWrite)
+    open(filename, fmWrite)
     --> col 2: system.Open
         col 3: proc (var File, string, FileMode, int): bool
         col 7:

doc/nimc.txt

@@ -393,12 +393,18 @@ Use two backticks to produce a single verbatim backtick.
 
 
 ImportCpp pragma
-----------------
+----------------
+
+**Note**: `c2nim <c2nim.html>`_ can parse a large subset of C++ and knows
+about the ``importcpp`` pragma pattern language. It is not necessary
+to know all the details described here.
+
+
 Similar to the `importc pragma for C <manual.html#importc-pragma>`_, the
-``importcpp`` pragma can be used to import `C++`:idx: methods. The generated
-code then uses the C++ method calling syntax: ``obj->method(arg)``.  In
-addition with the ``header`` and ``emit`` pragmas this allows *sloppy*
-interfacing with libraries written in C++:
+``importcpp`` pragma can be used to import `C++`:idx: methods or C++ symbols
+in general. The generated code then uses the C++ method calling 
+syntax: ``obj->method(arg)``.  In combination with the ``header`` and ``emit``
+pragmas this allows *sloppy* interfacing with libraries written in C++:
 
 .. code-block:: Nim
   # Horrible example of how to interface with a C++ engine ... ;-)
@@ -418,18 +424,168 @@ interfacing with libraries written in C++:
     irr = "<irrlicht/irrlicht.h>"
 
   type
-    IrrlichtDeviceObj {.final, header: irr, importc: "IrrlichtDevice".} = object
+    IrrlichtDeviceObj {.final, header: irr,
+                        importcpp: "IrrlichtDevice".} = object
     IrrlichtDevice = ptr IrrlichtDeviceObj
 
-  proc createDevice(): PIrrlichtDevice {.
-    header: irr, importc: "createDevice".}
-  proc run(device: PIrrlichtDevice): bool {.
-    header: irr, importcpp: "run".}
-  
+  proc createDevice(): IrrlichtDevice {.
+    header: irr, importcpp: "createDevice(@)".}
+  proc run(device: IrrlichtDevice): bool {.
+    header: irr, importcpp: "#.run(@)".}
+
 The compiler needs to be told to generate C++ (command ``cpp``) for 
 this to work. The conditional symbol ``cpp`` is defined when the compiler
-emits C++ code.
-
+emits C++ code.
+
+
+Namespaces
+~~~~~~~~~~
+
+The *sloppy interfacing* example uses ``.emit`` to produce ``using namespace``
+declarations. It is usually much better to instead refer to the imported name
+via the ``namespace::identifier`` notation:
+
+.. code-block:: nim
+  type
+    IrrlichtDeviceObj {.final, header: irr,
+                        importcpp: "irr::IrrlichtDevice".} = object
+
+
+Importcpp for enums
+~~~~~~~~~~~~~~~~~~~
+
+When ``importcpp`` is applied to an enum type the numerical enum values are
+annotated with the C++ enum type, like in this example: ``((TheCppEnum)(3))``.
+(This turned out to be the simplest way to implement it.)
+
+
+Importcpp for procs
+~~~~~~~~~~~~~~~~~~~
+
+Note that the ``importcpp`` variant for procs uses a somewhat cryptic pattern
+language for maximum flexibility:
+
+- A hash ``#`` symbol is replaced by the first or next argument.
+- A dot following the hash ``#.`` indicates that the call should use C++'s dot
+  or arrow notation.
+- An at symbol ``@`` is replaced by the remaining arguments, separated by
+  commas.
+
+For example:
+
+.. code-block:: nim
+  proc cppMethod(this: CppObj, a, b, c: cint) {.importcpp: "#.CppMethod(@)".}
+  var x: ptr CppObj
+  cppMethod(x[], 1, 2, 3)
+
+Produces:
+
+.. code-block:: C
+  x->CppMethod(1, 2, 3)
+
+As a special rule to keep backwards compatibility with older versions of the
+``importcpp`` pragma, if there is no special pattern
+character (any of ``# ' @``) at all, C++'s
+dot or arrow notation is assumed, so the above example can also be written as:
+
+.. code-block:: nim
+  proc cppMethod(this: CppObj, a, b, c: cint) {.importcpp: "CppMethod".}
+
+Note that the pattern language naturally also covers C++'s operator overloading
+capabilities:
+
+.. code-block:: nim
+  proc vectorAddition(a, b: Vec3): Vec3 {.importcpp: "# + #".}
+  proc dictLookup(a: Dict, k: Key): Value {.importcpp: "#[#]".}
+
+
+- An apostrophe ``'`` followed by an integer ``i`` in the range 0..9
+  is replaced by the i'th parameter *type*. The 0th position is the result
+  type. This can be used to pass types to C++ function templates. Between
+  the ``'`` and the digit an asterisk can be used to get to the base type
+  of the type. (So it "takes away a star" from the type; ``T*`` becomes ``T``.)
+  Two stars can be used to get to the element type of the element type etc.
+
+For example:
+
+.. code-block:: nim
+
+  type Input {.importcpp: "System::Input".} = object
+  proc getSubsystem*[T](): ptr T {.importcpp: "SystemManager::getSubsystem<'*0>()".}
+
+  let x: ptr Input = getSubsystem[Input]()
+
+Produces:
+
+.. code-block:: C
+  x = SystemManager::getSubsystem<System::Input>()
+
+
+- ``#@`` is a special case to support a ``cnew`` operation. It is required so
+  that the call expression is inlined directly, without going through a
+  temporary location. This is only required to circumvent a limitation of the
+  current code generator.
+
+For example C++'s ``new`` operator can be "imported" like this:
+
+.. code-block:: nim
+  proc cnew*[T](x: T): ptr T {.importcpp: "(new '*0#@)", nodecl.}
+
+  # constructor of 'Foo':
+  proc constructFoo(a, b: cint): Foo {.importcpp: "Foo(@)".}
+
+  let x = cnew constructFoo(3, 4)
+
+Produces:
+
+.. code-block:: C
+  x = new Foo(3, 4)
+
+However, depending on the use case ``new Foo`` can also be wrapped like this
+instead:
+
+.. code-block:: nim
+  proc newFoo(a, b: cint): ptr Foo {.importcpp: "new Foo(@)".}
+
+  let x = newFoo(3, 4)
+
+
+Wrapping destructors
+~~~~~~~~~~~~~~~~~~~~
+
+Since Nim generates C++ directly, any destructor is called implicitly by the
+C++ compiler at the scope exits. This means that often one can get away with
+not wrapping the destructor at all! However when it needs to be invoked
+explicitly, it needs to be wrapped. But the pattern language already provides
+everything that is required for that:
+
+.. code-block:: nim
+  proc destroyFoo(this: var Foo) {.importcpp: "#.~Foo()".}
+
+
+Importcpp for objects
+~~~~~~~~~~~~~~~~~~~~~
+
+Generic ``importcpp``'ed objects are mapped to C++ templates. This means that
+you can import C++'s templates rather easily without the need for a pattern
+language for object types:
+
+.. code-block:: nim
+  type
+    StdMap {.importcpp: "std::map", header: "<map>".} [K, V] = object
+  proc `[]=`[K, V](this: var StdMap[K, V]; key: K; val: V) {.
+    importcpp: "#[#] = #".}
+
+  var x: StdMap[cint, cdouble]
+  x[6] = 91.4
+
+
+Produces:
+
+.. code-block:: C
+  std::map<int, double> x;
+  x[6] = 91.4;
+
 
 ImportObjC pragma
 -----------------
@@ -607,7 +763,7 @@ line is an incomplete statement to be continued these rules are used:
 Nim for embedded systems
 ========================
 
-The standard library can be avoided to a point where C code generation 
+The standard library can be avoided to a point where C code generation
 for 16bit micro controllers is feasible. Use the `standalone`:idx: target
 (``--os:standalone``) for a bare bones standard library that lacks any
 OS features.
@@ -619,9 +775,9 @@ For example, to generate code for an `AVR`:idx: processor use this command::
   
   nim c --cpu:avr --os:standalone --deadCodeElim:on --genScript x.nim
 
-For the ``standalone`` target you need to provide 
-a file ``panicoverride.nim``. 
-See ``tests/manyloc/standalone/panicoverride.nim`` for an example 
+For the ``standalone`` target one needs to provide
+a file ``panicoverride.nim``.
+See ``tests/manyloc/standalone/panicoverride.nim`` for an example
 implementation.
 
 

lib/pure/collections/critbits.nim

@@ -12,7 +12,7 @@
 ## by Adam Langley.
 
 type
-  NodeObj[T] = object {.pure, final, acyclic.}
+  NodeObj[T] = object {.acyclic.}
     byte: int ## byte index of the difference
     otherbits: char
     case isLeaf: bool
@@ -23,11 +23,10 @@ type
         val: T
     
   Node[T] = ref NodeObj[T]
-  CritBitTree*[T] = object {.
-      pure, final.} ## The crit bit tree can either be used
-                    ## as a mapping from strings to
-                    ## some type ``T`` or as a set of
-                    ## strings if ``T`` is void.
+  CritBitTree*[T] = object ## The crit bit tree can either be used
+                           ## as a mapping from strings to
+                           ## some type ``T`` or as a set of
+                           ## strings if ``T`` is void.
     root: Node[T]
     count: int
 

lib/pure/collections/intsets.nim

@@ -8,7 +8,7 @@
 #
 
 ## The ``intsets`` module implements an efficient int set implemented as a
-## sparse bit set.
+## `sparse bit set`:idx:.
 ## **Note**: Since Nim currently does not allow the assignment operator to
 ## be overloaded, ``=`` for int sets performs some rather meaningless shallow
 ## copy; use ``assign`` to get a deep copy.

lib/pure/collections/queues.nim

@@ -7,7 +7,7 @@
 #    distribution, for details about the copyright.
 #
 
-## Implementation of a queue. The underlying implementation uses a ``seq``.
+## Implementation of a `queue`:idx:. The underlying implementation uses a ``seq``.
 ## Note: For inter thread communication use
 ## a `TChannel <channels.html>`_ instead.
 

lib/pure/collections/sets.nim

@@ -7,7 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
-## The ``sets`` module implements an efficient hash set and ordered hash set.
+## The ``sets`` module implements an efficient `hash set`:idx: and
+## ordered hash set.
 ##
 ## Hash sets are different from the `built in set type
 ## <manual.html#set-type>`_. Sets allow you to store any value that can be

lib/pure/collections/tables.nim

@@ -7,7 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
-## The ``tables`` module implements variants of an efficient hash table that is
+## The ``tables`` module implements variants of an efficient `hash table`:idx:
+## (also often named `dictionary`:idx: in other programming languages) that is
 ## a mapping from keys to values. ``Table`` is the usual hash table,
 ## ``OrderedTable`` is like ``Table`` but remembers insertion order
 ## and ``CountTable`` is a mapping from a key to its number of occurances.

todo.txt

@@ -1,7 +1,6 @@
 version 0.10
 ============
 
-- document the improved c++ support
 - improve the docs for inheritance
 - The bitwise 'not' operator will be renamed to 'bnot' to
   prevent 'not 4 == 5' from compiling. -> requires 'mixin' annotation for procs!