@@ -16,5 +16,7 @@ add_library(${PROJECT_NAME} INTERFACE)

 ## C++

 include(common.cmake)

 common(

+    DISABLE_CLANG_TIDY # TODO

+    DISABLE_CPPCHECK # TODO

     CXX_STANDARD 14

 )

@@ -2,6 +2,10 @@

 **C**oncept-based **R**elaying **Any** C++14 type.

+For a usage example, see `tests/crany.cpp`.

+

+For a diagram visualizing the implementation, see `doc/crany.dot.png`.

+

 [`crany`]: https://git.rcrnstn.net/rcrnstn/crany

 ## References

new file mode 100644

@@ -0,0 +1,19 @@

+digraph "Crany"

+{

+    edge [dir=back,arrowtail=empty]

+

+    "ModelSelf<Model<Self>>" -> "Concept<ModelSelf<Model<Self>>>" [label="self()"]

+    "Concept<ModelSelf<Model<Self>>>" -> "Model" [label="static relays"]

+

+    "ConceptSelf" -> "Concept<ConceptSelf>" [label="recursive self()"]

+    "Concept<ConceptSelf>" -> "CloneConcept" [label="dynamic definitions"]

+

+    "CranySelf<Crany<Concept>>" -> "Concept<CranySelf<Crany<Concept>>>" [label="self()"]

+    "Concept<CranySelf<Crany<Concept>>>" -> "Crany<Concept>" [label="static relays"]

+

+    "CloneConcept" -> "ModelSelf<Model<Self>>" [label="clone()" constraint=false]

+

+    "Crany<Concept>" -> "CloneConcept"  [label="self_" arrowtail=diamond constraint=false]

+

+    "Model" -> "Self" [label="self_" arrowtail=diamond]

+}

new file mode 100644

Binary files /dev/null and b/doc/crany.dot.png differ

new file mode 100644

@@ -0,0 +1,137 @@

+<?xml version="1.0" encoding="UTF-8" standalone="no"?>

+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"

+ "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

+<!-- Generated by graphviz version 2.43.0 (0)

+ -->

+<!-- Title: Crany Pages: 1 -->

+<svg width="787pt" height="328pt"

+ viewBox="0.00 0.00 787.00 328.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">

+<g id="graph0" class="graph" transform="scale(1 1) rotate(0) translate(4 324)">

+<title>Crany</title>

+<polygon fill="white" stroke="transparent" points="-4,4 -4,-324 783,-324 783,4 -4,4"/>

+<text text-anchor="middle" x="389.5" y="-304.8" font-family="Arial" font-size="14.00" fill="grey">Crany</text>

+<!-- ModelSelf&lt;Model&lt;Self&gt;&gt; -->

+<g id="node1" class="node">

+<title>ModelSelf&lt;Model&lt;Self&gt;&gt;</title>

+<path fill="none" stroke="black" d="M192.5,-297C192.5,-297 45.5,-297 45.5,-297 39.5,-297 33.5,-291 33.5,-285 33.5,-285 33.5,-273 33.5,-273 33.5,-267 39.5,-261 45.5,-261 45.5,-261 192.5,-261 192.5,-261 198.5,-261 204.5,-267 204.5,-273 204.5,-273 204.5,-285 204.5,-285 204.5,-291 198.5,-297 192.5,-297"/>

+<text text-anchor="middle" x="119" y="-275.3" font-family="Arial" font-size="14.00">ModelSelf&lt;Model&lt;Self&gt;&gt;</text>

+</g>

+<!-- Concept&lt;ModelSelf&lt;Model&lt;Self&gt;&gt;&gt; -->

+<g id="node2" class="node">

+<title>Concept&lt;ModelSelf&lt;Model&lt;Self&gt;&gt;&gt;</title>

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+<text text-anchor="middle" x="119" y="-188.3" font-family="Arial" font-size="14.00">Concept&lt;ModelSelf&lt;Model&lt;Self&gt;&gt;&gt;</text>

+</g>

+<!-- ModelSelf&lt;Model&lt;Self&gt;&gt;&#45;&gt;Concept&lt;ModelSelf&lt;Model&lt;Self&gt;&gt;&gt; -->

+<g id="edge1" class="edge">

+<title>ModelSelf&lt;Model&lt;Self&gt;&gt;&#45;&gt;Concept&lt;ModelSelf&lt;Model&lt;Self&gt;&gt;&gt;</title>

+<path fill="none" stroke="black" d="M119,-250.73C119,-237.42 119,-221.81 119,-210.18"/>

+<polygon fill="none" stroke="black" points="115.5,-250.8 119,-260.8 122.5,-250.8 115.5,-250.8"/>

+<text text-anchor="middle" x="137.5" y="-231.8" font-family="Times,serif" font-size="14.00">self()</text>

+</g>

+<!-- Model -->

+<g id="node3" class="node">

+<title>Model</title>

+<path fill="none" stroke="black" d="M134,-123C134,-123 104,-123 104,-123 98,-123 92,-117 92,-111 92,-111 92,-99 92,-99 92,-93 98,-87 104,-87 104,-87 134,-87 134,-87 140,-87 146,-93 146,-99 146,-99 146,-111 146,-111 146,-117 140,-123 134,-123"/>

+<text text-anchor="middle" x="119" y="-101.3" font-family="Arial" font-size="14.00">Model</text>

+</g>

+<!-- Concept&lt;ModelSelf&lt;Model&lt;Self&gt;&gt;&gt;&#45;&gt;Model -->

+<g id="edge2" class="edge">

+<title>Concept&lt;ModelSelf&lt;Model&lt;Self&gt;&gt;&gt;&#45;&gt;Model</title>

+<path fill="none" stroke="black" d="M119,-163.73C119,-150.42 119,-134.81 119,-123.18"/>

+<polygon fill="none" stroke="black" points="115.5,-163.8 119,-173.8 122.5,-163.8 115.5,-163.8"/>

+<text text-anchor="middle" x="163" y="-144.8" font-family="Times,serif" font-size="14.00">static relays</text>

+</g>

+<!-- Self -->

+<g id="node4" class="node">

+<title>Self</title>

+<path fill="none" stroke="black" d="M134,-36C134,-36 104,-36 104,-36 98,-36 92,-30 92,-24 92,-24 92,-12 92,-12 92,-6 98,0 104,0 104,0 134,0 134,0 140,0 146,-6 146,-12 146,-12 146,-24 146,-24 146,-30 140,-36 134,-36"/>

+<text text-anchor="middle" x="119" y="-14.3" font-family="Arial" font-size="14.00">Self</text>

+</g>

+<!-- Model&#45;&gt;Self -->

+<g id="edge3" class="edge">

+<title>Model&#45;&gt;Self</title>

+<path fill="none" stroke="black" d="M119,-74.74C119,-61.88 119,-47.23 119,-36.18"/>

+<polygon fill="black" stroke="black" points="119,-74.8 123,-80.8 119,-86.8 115,-80.8 119,-74.8"/>

+<text text-anchor="middle" x="135.5" y="-57.8" font-family="Times,serif" font-size="14.00">self_</text>

+</g>

+<!-- ConceptSelf -->

+<g id="node5" class="node">

+<title>ConceptSelf</title>

+<path fill="none" stroke="black" d="M453,-297C453,-297 387,-297 387,-297 381,-297 375,-291 375,-285 375,-285 375,-273 375,-273 375,-267 381,-261 387,-261 387,-261 453,-261 453,-261 459,-261 465,-267 465,-273 465,-273 465,-285 465,-285 465,-291 459,-297 453,-297"/>

+<text text-anchor="middle" x="420" y="-275.3" font-family="Arial" font-size="14.00">ConceptSelf</text>

+</g>

+<!-- Concept&lt;ConceptSelf&gt; -->

+<g id="node6" class="node">

+<title>Concept&lt;ConceptSelf&gt;</title>

+<path fill="none" stroke="black" d="M486.5,-210C486.5,-210 353.5,-210 353.5,-210 347.5,-210 341.5,-204 341.5,-198 341.5,-198 341.5,-186 341.5,-186 341.5,-180 347.5,-174 353.5,-174 353.5,-174 486.5,-174 486.5,-174 492.5,-174 498.5,-180 498.5,-186 498.5,-186 498.5,-198 498.5,-198 498.5,-204 492.5,-210 486.5,-210"/>

+<text text-anchor="middle" x="420" y="-188.3" font-family="Arial" font-size="14.00">Concept&lt;ConceptSelf&gt;</text>

+</g>

+<!-- ConceptSelf&#45;&gt;Concept&lt;ConceptSelf&gt; -->

+<g id="edge4" class="edge">

+<title>ConceptSelf&#45;&gt;Concept&lt;ConceptSelf&gt;</title>

+<path fill="none" stroke="black" d="M420,-250.73C420,-237.42 420,-221.81 420,-210.18"/>

+<polygon fill="none" stroke="black" points="416.5,-250.8 420,-260.8 423.5,-250.8 416.5,-250.8"/>

+<text text-anchor="middle" x="474" y="-231.8" font-family="Times,serif" font-size="14.00">recursive self()</text>

+</g>

+<!-- CloneConcept -->

+<g id="node7" class="node">

+<title>CloneConcept</title>

+<path fill="none" stroke="black" d="M459,-123C459,-123 381,-123 381,-123 375,-123 369,-117 369,-111 369,-111 369,-99 369,-99 369,-93 375,-87 381,-87 381,-87 459,-87 459,-87 465,-87 471,-93 471,-99 471,-99 471,-111 471,-111 471,-117 465,-123 459,-123"/>

+<text text-anchor="middle" x="420" y="-101.3" font-family="Arial" font-size="14.00">CloneConcept</text>

+</g>

+<!-- Concept&lt;ConceptSelf&gt;&#45;&gt;CloneConcept -->

+<g id="edge5" class="edge">

+<title>Concept&lt;ConceptSelf&gt;&#45;&gt;CloneConcept</title>

+<path fill="none" stroke="black" d="M420,-163.73C420,-150.42 420,-134.81 420,-123.18"/>

+<polygon fill="none" stroke="black" points="416.5,-163.8 420,-173.8 423.5,-163.8 416.5,-163.8"/>

+<text text-anchor="middle" x="490.5" y="-144.8" font-family="Times,serif" font-size="14.00">dynamic definitions</text>

+</g>

+<!-- CloneConcept&#45;&gt;ModelSelf&lt;Model&lt;Self&gt;&gt; -->

+<g id="edge6" class="edge">

+<title>CloneConcept&#45;&gt;ModelSelf&lt;Model&lt;Self&gt;&gt;</title>

+<path fill="none" stroke="black" d="M367.44,-127.24C340.96,-139.12 309.02,-155.3 283,-174 264.62,-187.2 265.19,-196.54 247,-210 219.28,-230.5 184.57,-248.53 158.29,-260.87"/>

+<polygon fill="none" stroke="black" points="369.19,-130.29 376.94,-123.06 366.37,-123.89 369.19,-130.29"/>

+<text text-anchor="middle" x="307.5" y="-188.3" font-family="Times,serif" font-size="14.00">clone()</text>

+</g>

+<!-- CranySelf&lt;Crany&lt;Concept&gt;&gt; -->

+<g id="node8" class="node">

+<title>CranySelf&lt;Crany&lt;Concept&gt;&gt;</title>

+<path fill="none" stroke="black" d="M733.5,-297C733.5,-297 562.5,-297 562.5,-297 556.5,-297 550.5,-291 550.5,-285 550.5,-285 550.5,-273 550.5,-273 550.5,-267 556.5,-261 562.5,-261 562.5,-261 733.5,-261 733.5,-261 739.5,-261 745.5,-267 745.5,-273 745.5,-273 745.5,-285 745.5,-285 745.5,-291 739.5,-297 733.5,-297"/>

+<text text-anchor="middle" x="648" y="-275.3" font-family="Arial" font-size="14.00">CranySelf&lt;Crany&lt;Concept&gt;&gt;</text>

+</g>

+<!-- Concept&lt;CranySelf&lt;Crany&lt;Concept&gt;&gt;&gt; -->

+<g id="node9" class="node">

+<title>Concept&lt;CranySelf&lt;Crany&lt;Concept&gt;&gt;&gt;</title>

+<path fill="none" stroke="black" d="M767,-210C767,-210 529,-210 529,-210 523,-210 517,-204 517,-198 517,-198 517,-186 517,-186 517,-180 523,-174 529,-174 529,-174 767,-174 767,-174 773,-174 779,-180 779,-186 779,-186 779,-198 779,-198 779,-204 773,-210 767,-210"/>

+<text text-anchor="middle" x="648" y="-188.3" font-family="Arial" font-size="14.00">Concept&lt;CranySelf&lt;Crany&lt;Concept&gt;&gt;&gt;</text>

+</g>

+<!-- CranySelf&lt;Crany&lt;Concept&gt;&gt;&#45;&gt;Concept&lt;CranySelf&lt;Crany&lt;Concept&gt;&gt;&gt; -->

+<g id="edge7" class="edge">

+<title>CranySelf&lt;Crany&lt;Concept&gt;&gt;&#45;&gt;Concept&lt;CranySelf&lt;Crany&lt;Concept&gt;&gt;&gt;</title>

+<path fill="none" stroke="black" d="M648,-250.73C648,-237.42 648,-221.81 648,-210.18"/>

+<polygon fill="none" stroke="black" points="644.5,-250.8 648,-260.8 651.5,-250.8 644.5,-250.8"/>

+<text text-anchor="middle" x="666.5" y="-231.8" font-family="Times,serif" font-size="14.00">self()</text>

+</g>

+<!-- Crany&lt;Concept&gt; -->

+<g id="node10" class="node">

+<title>Crany&lt;Concept&gt;</title>

+<path fill="none" stroke="black" d="M695.5,-123C695.5,-123 600.5,-123 600.5,-123 594.5,-123 588.5,-117 588.5,-111 588.5,-111 588.5,-99 588.5,-99 588.5,-93 594.5,-87 600.5,-87 600.5,-87 695.5,-87 695.5,-87 701.5,-87 707.5,-93 707.5,-99 707.5,-99 707.5,-111 707.5,-111 707.5,-117 701.5,-123 695.5,-123"/>

+<text text-anchor="middle" x="648" y="-101.3" font-family="Arial" font-size="14.00">Crany&lt;Concept&gt;</text>

+</g>

+<!-- Concept&lt;CranySelf&lt;Crany&lt;Concept&gt;&gt;&gt;&#45;&gt;Crany&lt;Concept&gt; -->

+<g id="edge8" class="edge">

+<title>Concept&lt;CranySelf&lt;Crany&lt;Concept&gt;&gt;&gt;&#45;&gt;Crany&lt;Concept&gt;</title>

+<path fill="none" stroke="black" d="M648,-163.73C648,-150.42 648,-134.81 648,-123.18"/>

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+</g>

+<!-- Crany&lt;Concept&gt;&#45;&gt;CloneConcept -->

+<g id="edge9" class="edge">

+<title>Crany&lt;Concept&gt;&#45;&gt;CloneConcept</title>

+<path fill="none" stroke="black" d="M575.88,-105C541.85,-105 502.04,-105 471.17,-105"/>

+<polygon fill="black" stroke="black" points="576.12,-105 582.12,-101 588.12,-105 582.12,-109 576.12,-105"/>

+<text text-anchor="middle" x="529.75" y="-111.8" font-family="Times,serif" font-size="14.00">self_</text>

+</g>

+</g>

+</svg>

new file mode 100644

@@ -0,0 +1,139 @@

+#ifndef CRANY_HPP_

+#define CRANY_HPP_

+

+

+#include <memory>

+#include <type_traits>

+#include <cassert>

+

+

+template<template<typename> class = std::is_void>

+class Crany;

+

+/// CranySelf

+template<>

+class Crany<>

+{

+private:

+    template<template<typename> class> friend class Crany;

+    template<typename T>

+    struct CranySelf

+    {

+    protected:

+        auto       & self()       { return *((T       *)this)->self_; }

+        auto const & self() const { return *((T const *)this)->self_; }

+        virtual ~CranySelf() = default;

+    };

+};

+

+/// Crany

+template<template<typename> class Concept>

+class Crany final : public Concept<Crany<>::CranySelf<Crany<Concept>>>

+{

+public:

+

+    /// Special member functions

+    template<typename Self>

+    Crany(Self self) : self_{new Model<Self>(std::move(self))} {}

+    Crany(Crany const & other) : self_(other.self_->clone()) {}

+    Crany & operator=(Crany const & other) { return *this = Crany(other); }

+    Crany(Crany && other) = default;

+    Crany & operator=(Crany && other) = default;

+

+private:

+

+    /// CranySelf

+    friend Crany<>::CranySelf<Crany<Concept>>;

+

+    /// ConceptSelf

+    struct ConceptSelf

+    {

+    protected:

+        auto       & self()       { assert(!"Crany Concept non-virtual member function called"); return *(Concept<ConceptSelf>       *)this; }

+        auto const & self() const { assert(!"Crany Concept non-virtual member function called"); return *(Concept<ConceptSelf> const *)this; }

+        virtual ~ConceptSelf() = default;

+    };

+

+    /// CloneConcept

+    struct CloneConcept : Concept<ConceptSelf>

+    {

+        virtual CloneConcept * clone() const = 0;

+    };

+

+    /// ModelSelf

+    template<typename T>

+    struct ModelSelf : CloneConcept

+    {

+    protected:

+        auto       & self()       { return ((T       *)this)->self_; }

+        auto const & self() const { return ((T const *)this)->self_; }

+    };

+

+    /// Model

+    template<typename Self>

+    struct Model final : Concept<ModelSelf<Model<Self>>>

+    {

+        Model(Self self) : self_{std::move(self)} {}

+        CloneConcept * clone() const { return new Model<Self>(*this); }

+        Self self_;

+    };

+

+    /// Self

+    std::unique_ptr<CloneConcept> self_;

+

+    /// crany_cast

+    template<typename T, typename Crany> friend T const * crany_cast(Crany const *  crany) noexcept;

+    template<typename T, typename Crany> friend T       * crany_cast(Crany       *  crany) noexcept;

+    template<typename T, typename Crany> friend T         crany_cast(Crany const &  crany);

+    template<typename T, typename Crany> friend T         crany_cast(Crany       &  crany);

+    template<typename T, typename Crany> friend T         crany_cast(Crany       && crany);

+};

+

+/// bad_crany_cast

+class bad_crany_cast : public std::bad_cast

+{

+};

+

+/// crany_cast

+template<typename T, typename Crany>

+T const * crany_cast(Crany const * crany) noexcept

+{

+    if (!crany)

+        return nullptr;

+    using Model = typename Crany::Model<T>;

+    if (auto * model = dynamic_cast<Model *>(crany->self_.get()))

+        return &model->self_;

+    return nullptr;

+}

+template<typename T, typename Crany>

+T * crany_cast(Crany * crany) noexcept

+{

+    return const_cast<T *>(*const_cast<T const *>(crany));

+}

+template<typename T, typename Crany>

+T crany_cast(Crany const & crany)

+{

+    using U = std::remove_cv_t<std::remove_reference_t<T>>;

+    if (auto p = crany_cast<U>(&crany))

+        return static_cast<T>(*p);

+    throw bad_crany_cast(); // TODO

+}

+template<typename T, typename Crany>

+T crany_cast(Crany & crany)

+{

+    using U = std::remove_cv_t<std::remove_reference_t<T>>;

+    if (auto p = crany_cast<U>(&crany))

+        return static_cast<T>(*p);

+    throw bad_crany_cast(); // TODO

+}

+template<typename T, typename Crany>

+T crany_cast(Crany && crany)

+{

+    using U = std::remove_cv_t<std::remove_reference_t<T>>;

+    if (auto p = crany_cast<U>(&crany))

+        return static_cast<T>(std::move(*p));

+    throw bad_crany_cast(); // TODO

+}

+

+

+#endif // CRANY_HPP_

new file mode 100644

@@ -0,0 +1,59 @@

+#include "crany.hpp"

+

+#include <cmath>

+#include <iostream>

+#include <vector>

+

+

+auto constexpr pi = std::acos(-1.0F);

+

+

+struct Circle

+{

+    float radius;

+    void  scale(float scale)       { radius *= scale;         }

+    float area()             const { return pi*radius*radius; }

+    float circumference()    const { return 2.0F*pi*radius;   }

+};

+

+struct Rectangle

+{

+    float side1;

+    float side2;

+    void  scale(float scale)       { side1 *= scale; side2 *= scale; }

+    float area()             const { return side1*side2;             }

+};

+

+

+template<typename Self>

+struct ShapeConcept : Self

+{

+    using Self::self;

+    virtual void  scale(float value)       { return self().scale(value); }

+    virtual float area()             const { return self().area();       }

+};

+

+using Shape = Crany<ShapeConcept>;

+using Shapes = std::vector<Shape>;

+

+

+int main()

+{

+    static_assert(std::is_standard_layout   <Circle>{}, "Circle not is standard layout");

+    static_assert(std::is_trivially_copyable<Circle>{}, "Circle not is trivially copyable");

+

+    auto shapes = Shapes{

+        Circle{1.0F},

+        Rectangle{2.0F, 3.0F},

+    };

+    shapes.push_back(shapes.front());

+    shapes.back().scale(2.0F);

+

+    std::cout << std::boolalpha;

+    for (auto const & shape : shapes)

+        std::cout

+            << shape.area()

+            << " "

+            << bool(crany_cast<Circle>(&shape))

+            << "\n";

+}