discard """ targets: "cpp" cmd: "nim cpp $file" output: ''' 1 0 123 0 123 ___ 0 777 10 123 0 777 10 123 () ''' """ {.emit:"""/*TYPESECTION*/ struct CppClass { int x; int y; CppClass(int inX, int inY) { this->x = inX; this->y = inY; } //CppClass() = default; }; """.} type CppClass* {.importcpp, inheritable.} = object x: int32 y: int32 proc makeCppClass(x, y: int32): CppClass {.importcpp: "CppClass(@)", constructor.} #test globals are init with the constructor call var shouldCompile {.used.} = makeCppClass(1, 2) proc newCpp*[T](): ptr T {.importcpp:"new '*0()".} #creation type NimClassNoNarent* = object x: int32 proc makeNimClassNoParent(x:int32): NimClassNoNarent {. constructor.} = result.x = x discard let nimClassNoParent = makeNimClassNoParent(1) echo nimClassNoParent.x #acess to this just fine. Notice the field will appear last because we are dealing with constructor calls here var nimClassNoParentDef {.used.}: NimClassNoNarent #test has a default constructor. #inheritance type NimClass* = object of CppClass proc makeNimClass(x:int32): NimClass {. constructor:"NimClass('1 #1) : CppClass(0, #1) ".} = result.x = x #optinially define the default constructor so we get rid of the cpp warn and we can declare the obj (note: default constructor of 'tyObject_NimClass__apRyyO8cfRsZtsldq1rjKA' is implicitly deleted because base class 'CppClass' has no default constructor) proc makeCppClass(): NimClass {. constructor: "NimClass() : CppClass(0, 0) ".} = result.x = 1 let nimClass = makeNimClass(1) var nimClassDef {.used.}: NimClass #since we explictly defined the default constructor we can declare the obj #bug: 22662 type BugClass* = object x: int # Not initialized proc makeBugClass(): BugClass {.constructor.} = discard proc main = for i in 0 .. 1: var n = makeBugClass() echo n.x n.x = 123 echo n.x main() #bug: echo "___" type NimClassWithDefault = object x: int y = 777 case kind: bool = true of true: z: int = 10 else: discard proc makeNimClassWithDefault(): NimClassWithDefault {.constructor.} = result = NimClassWithDefault() proc init = for i in 0 .. 1: var n = makeNimClassWithDefault() echo n.x echo n.y echo n.z n.x = 123 echo n.x init() #tests that the ctor is not declared with nodecl. #nodelc also prevents the creation of a default one when another is created. type Foo {.exportc.} = object proc makeFoo(): Foo {.used, constructor, nodecl.} = discard echo $Foo() type Boo = object proc `=copy`(dest: var Boo; src: Boo) = discard proc makeBoo(): Boo {.constructor.} = Boo() proc makeBoo2(): Boo = Boo() block: proc main = var b = makeBoo() var b2 = makeBoo2() main()