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xtl.cpp
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//
// Mach7: Pattern Matching Library for C++
//
// Copyright 2011-2013, Texas A&M University.
// Copyright 2014 Yuriy Solodkyy.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// * Neither the names of Mach7 project nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
// IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
///
/// \file
///
/// This file is a part of Mach7 library test suite.
///
/// \author Yuriy Solodkyy <[email protected]>
///
/// \see https://parasol.tamu.edu/xtl/
/// \see https://parasol.tamu.edu/mach7/
/// \see https://github.com/solodon4/Mach7
/// \see https://github.com/solodon4/SELL
///
#ifndef HAS_BOOST
#include <iostream>
int main() {
std::cout << "This test requires Boost!\n";
return 1;
}
#else
#include <iostream>
#include <boost/variant.hpp>
#include <mach7/type_switchN-patterns-xtl.hpp> // Support for N-ary Match statement on patterns with arbitrary subtyping relation
#include <mach7/adapters/boost/adapt_boost_variant.hpp> // Mach7 adapters for boost::variant
#include <mach7/patterns/constructor.hpp> // Support for constructor patterns
#include <mach7/patterns/primitive.hpp> // Wildcard, variable and value patterns
//----------------------------------------------------------------------------------------------------------------------
static_assert(xtl::is_subtype<int,int>::value,"No reflexivity");
/// Experimenting with extending XTL subtyping mechanism to also have an equivalent of checked downcast.
void test_variant_subtyping()
{
// Since any value that int can hold can be held inside that variant (semantic subtyping)
static_assert(xtl::is_subtype<int,boost::variant<double,float,int,unsigned int*>>::value, "Not a subtype");
typedef boost::variant<double,float,int,unsigned int*> my_variant_1;
std::cout << "===========" << std::endl;
{
my_variant_1 v1 = xtl::subtype_cast<my_variant_1>(3.1415);
std::cout << '(' << v1.which() << ',' << v1 << ')' << std::endl;
my_variant_1 v2 = xtl::subtype_cast<my_variant_1>(42);
std::cout << '(' << v2.which() << ',' << v2 << ')' << std::endl;
std::cout << "-----------" << std::endl;
double* p1 = xtl::subtype_dynamic_cast<double*>(&v1); std::cout << '(' << p1 << ',' << (p1 ? *p1 : 99999) << ')' << std::endl;
float* p2 = xtl::subtype_dynamic_cast<float* >(&v1); std::cout << '(' << p2 << ',' << (p2 ? *p2 : 88888) << ')' << std::endl;
int* p3 = xtl::subtype_dynamic_cast<int* >(&v1); std::cout << '(' << p3 << ',' << (p3 ? *p3 : 77777) << ')' << std::endl;
double* q1 = xtl::subtype_dynamic_cast<double*>(&v2); std::cout << '(' << q1 << ',' << (q1 ? *q1 : 66666) << ')' << std::endl;
float* q2 = xtl::subtype_dynamic_cast<float* >(&v2); std::cout << '(' << q2 << ',' << (q2 ? *q2 : 55555) << ')' << std::endl;
int* q3 = xtl::subtype_dynamic_cast<int* >(&v2); std::cout << '(' << q3 << ',' << (q3 ? *q3 : 44444) << ')' << std::endl;
std::cout << "sizeof(intptr_t)" << sizeof(std::intptr_t) << std::endl;
std::cout << "sizeof(v1.which_)" << sizeof(v1.which()) << std::endl;
}
std::cout << "===========" << std::endl;
{
const my_variant_1 v1 = xtl::subtype_cast<my_variant_1>(3.1415);
std::cout << '(' << v1.which() << ',' << v1 << ')' << std::endl;
const my_variant_1 v2 = xtl::subtype_cast<my_variant_1>(42);
std::cout << '(' << v2.which() << ',' << v2 << ')' << std::endl;
std::cout << "-----------" << std::endl;
const double* p1 = xtl::subtype_dynamic_cast<const double*>(&v1); std::cout << '(' << p1 << ',' << (p1 ? *p1 : 99999) << ')' << std::endl;
const float* p2 = xtl::subtype_dynamic_cast<const float* >(&v1); std::cout << '(' << p2 << ',' << (p2 ? *p2 : 88888) << ')' << std::endl;
const int* p3 = xtl::subtype_dynamic_cast<const int* >(&v1); std::cout << '(' << p3 << ',' << (p3 ? *p3 : 77777) << ')' << std::endl;
const double* q1 = xtl::subtype_dynamic_cast<const double*>(&v2); std::cout << '(' << q1 << ',' << (q1 ? *q1 : 66666) << ')' << std::endl;
const float* q2 = xtl::subtype_dynamic_cast<const float* >(&v2); std::cout << '(' << q2 << ',' << (q2 ? *q2 : 55555) << ')' << std::endl;
const int* q3 = xtl::subtype_dynamic_cast<const int* >(&v2); std::cout << '(' << q3 << ',' << (q3 ? *q3 : 44444) << ')' << std::endl;
}
using namespace mch;
var<double> d;
var<float> f;
var<int> n;
var<unsigned int*> p;
std::cout << "===========" << std::endl;
my_variant_1 vars[3] = {42, 3.14f, 9.876};
for (int k = 0; k < 2; ++k)
for (int i = 0; i < 3; ++i)
{
Match(vars[i])
{
Case(C<double>(d)) std::cout << "double " << d << std::endl; match0 += 1.0; break;
Case(C<float> (f)) std::cout << "float " << f << std::endl; match0 -= 1.0; break;
Case(C<int> (n)) std::cout << "int " << n << std::endl; match0++; break;
}
EndMatch
}
const my_variant_1 vars2[6] = {42, 3.14f, 9.876, 7, 2.72f, 1.2345};
for (int i = 0; i < 6; ++i)
{
Match(vars2[i])
{
Case(C<double>(d)) std::cout << "double " << d << std::endl; break;
Case(C<float> (f)) std::cout << "float " << f << std::endl; break;
Case(C<int> (n)) std::cout << "int " << n << std::endl; break;
// Case(C<unsigned int*>(p)) std::cout << "unsigned int* " << p << "->" << *p << std::endl; break; // FIX: fails to compile
}
EndMatch
}
// Match on 2 arguments
var<double> q;
var<float> l;
var<int> m;
for (int i = 0; i < 3; ++i)
for (int j = 0; j < 6; ++j)
{
Match(vars[i], vars2[j])
{
Case(C<double>(d), C<double>(q)) std::cout << "double " << d << "\t double " << q << std::endl; match0 += 1.0; break;
Case(C<float> (f), C<double>(q)) std::cout << "float " << f << "\t double " << q << std::endl; match0 -= 1.0; break;
Case(C<int> (n), C<double>(q)) std::cout << "int " << n << "\t double " << q << std::endl; match0++; break;
Case(C<double>(d), C<float>(l) ) std::cout << "double " << d << "\t float " << l << std::endl; match0 += 1.0; break;
Case(C<float> (f), C<float>(l) ) std::cout << "float " << f << "\t float " << l << std::endl; match0 -= 1.0; break;
Case(C<int> (n), C<float>(l) ) std::cout << "int " << n << "\t float " << l << std::endl; match0++; break;
Case(C<double>(d), C<int>(m) ) std::cout << "double " << d << "\t int " << m << std::endl; match0 += 1.0; break;
Case(C<float> (f), C<int>(m) ) std::cout << "float " << f << "\t int " << m << std::endl; match0 -= 1.0; break;
Case(C<int> (n), C<int>(m) ) std::cout << "int " << n << "\t int " << m << std::endl; match0++; break;
}
EndMatch
}
}
struct M { char im; M(char m = 0) : im(m) {} };
struct N { double in; N(double n = 0.0) : in(n) {} };
std::ostream& operator<<(std::ostream& os, const M& m) { return os << m.im; } // Helper to allow printing of M
std::ostream& operator<<(std::ostream& os, const N& n) { return os << n.in; } // Helper to allow printing of N
typedef boost::variant<M, N> VM;
/// Tests mutability of the subject and binding by reference
void test_variant_mutation()
{
using namespace mch;
VM vm[2] = { M('A'), N(3.1415926) };
for (size_t i = 0; i < 2; ++i)
{
Match(vm[i])
{
Case(C<M>()) match0.im = 'm'; break;
Case(C<N>()) match0.in = 2*match0.in; break;
}
EndMatch
}
for (size_t i = 0; i < 2; ++i)
{
var<M&> m; var<N&> n; // Demonstrates assignment to the actual subject via variable patterns of reference type
Match(vm[i])
{
Case(C<M>(m))
std::cout << "M -> " << match0.im << '=' << m << std::endl;
m = M('X');
std::cout << "M -> " << match0.im << '=' << m << std::endl;
break;
Case(C<N>(n))
std::cout << "N -> " << match0.in << '=' << n << std::endl;
n = N(42);
std::cout << "N -> " << match0.in << '=' << n << std::endl;
break;
}
EndMatch
}
}
//----------------------------------------------------------------------------------------------------------------------
struct A { int a; virtual void foo() { std::cout << "A" << std::endl; } virtual void foo() const { std::cout << "const A" << std::endl; } A() {} };
struct B : A { int b; virtual void foo() { std::cout << "B" << std::endl; } virtual void foo() const { std::cout << "const B" << std::endl; } B() {} };
struct C : A { double c; virtual void foo() { std::cout << "C" << std::endl; } virtual void foo() const { std::cout << "const C" << std::endl; } };
struct D : C, B { float d; virtual void foo() { std::cout << "D" << std::endl; } virtual void foo() const { std::cout << "const D" << std::endl; } };
struct X : virtual A { char x; virtual void foo() { std::cout << "X" << std::endl; } virtual void foo() const { std::cout << "const X" << std::endl; } };
struct Y : virtual A { short y; virtual void foo() { std::cout << "Y" << std::endl; } virtual void foo() const { std::cout << "const Y" << std::endl; } };
struct Z : X, Y { char z; virtual void foo() { std::cout << "Z" << std::endl; } virtual void foo() const { std::cout << "const Z" << std::endl; } };
static_assert( xtl::is_subtype< B , A >::value, " B <: A ");
static_assert( xtl::is_subtype< B*, A*>::value, " B* <: A*");
static_assert( xtl::is_subtype<const B*, const A*>::value, "const B* <: const A*");
static_assert( xtl::is_subtype< B*, const A*>::value, " B* <: const A*");
static_assert(!xtl::is_subtype<const B*, A*>::value, "const B* <: A*");
static_assert(!xtl::is_subtype< A , B >::value, " A <: B ");
static_assert(!xtl::is_subtype< A*, B*>::value, " A* <: B*");
static_assert(!xtl::is_subtype<const A*, const B*>::value, "const A* <: const B*");
static_assert(!xtl::is_subtype< A*, const B*>::value, " A* <: const B*");
static_assert(!xtl::is_subtype<const A*, B*>::value, "const A* <: B*");
/// Tests new XTL functionaliy on subtyping induced by subclassing
void test_subtype_dynamic_cast()
{
A a; const A ca;
B b; const B cb;
a = xtl::subtype_cast<A>(b);
a = xtl::subtype_cast<A>(cb);
//b = xtl::subtype_cast<B>(a); // error
A* qa = xtl::subtype_cast<A*>(&b);
const A* qaa= xtl::subtype_cast<const A*>(&cb); XTL_UNUSED(qaa);
//B* qb = xtl::subtype_cast<B*>(&a); // error
B* qb = xtl::subtype_dynamic_cast<B*>(qa);
qa->foo();
if (qb) qb->foo();
std::cout << "===========" << std::endl;
{
A* pA = new A;
B* pB = new B;
C* pC = new C;
D* pD = new D;
X* pX = new X;
Y* pY = new Y;
Z* pZ = new Z;
A* pa = xtl::subtype_cast<A*>(pA);
A* pb = xtl::subtype_cast<A*>(pB);
A* pc = xtl::subtype_cast<A*>(pC);
A* pdb= xtl::subtype_cast<A*>(static_cast<B*>(pD));
A* pdc= xtl::subtype_cast<A*>(static_cast<C*>(pD));
A* px = xtl::subtype_cast<A*>(pX);
A* py = xtl::subtype_cast<A*>(pY);
A* pz = xtl::subtype_cast<A*>(pZ);
if (A* p = xtl::subtype_dynamic_cast<A*>(pa)) p->foo();
if (B* p = xtl::subtype_dynamic_cast<B*>(pb)) p->foo();
if (C* p = xtl::subtype_dynamic_cast<C*>(pc)) p->foo();
if (D* p = xtl::subtype_dynamic_cast<D*>(pdb))p->foo();
if (D* p = xtl::subtype_dynamic_cast<D*>(pdc))p->foo();
if (X* p = xtl::subtype_dynamic_cast<X*>(px)) p->foo();
if (Y* p = xtl::subtype_dynamic_cast<Y*>(py)) p->foo();
if (Z* p = xtl::subtype_dynamic_cast<Z*>(pz)) p->foo();
if (B* p = xtl::subtype_dynamic_cast<B*>(pdc))p->foo();
if (C* p = xtl::subtype_dynamic_cast<C*>(pdb))p->foo();
if (const A* p = xtl::subtype_dynamic_cast<const A*>(pa)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pb)) p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pc)) p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pdb))p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pdc))p->foo();
if (const X* p = xtl::subtype_dynamic_cast<const X*>(px)) p->foo();
if (const Y* p = xtl::subtype_dynamic_cast<const Y*>(py)) p->foo();
if (const Z* p = xtl::subtype_dynamic_cast<const Z*>(pz)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pdc))p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pdb))p->foo();
}
{
const A* pA = new A;
const B* pB = new B;
const C* pC = new C;
const D* pD = new D;
const X* pX = new X;
const Y* pY = new Y;
const Z* pZ = new Z;
const A* pa = xtl::subtype_cast<const A*>(pA);
const A* pb = xtl::subtype_cast<const A*>(pB);
const A* pc = xtl::subtype_cast<const A*>(pC);
const A* pdb= xtl::subtype_cast<const A*>(static_cast<const B*>(pD));
const A* pdc= xtl::subtype_cast<const A*>(static_cast<const C*>(pD));
const A* px = xtl::subtype_cast<const A*>(pX);
const A* py = xtl::subtype_cast<const A*>(pY);
const A* pz = xtl::subtype_cast<const A*>(pZ);
if (const A* p = xtl::subtype_dynamic_cast<const A*>(pa)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pb)) p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pc)) p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pdb))p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pdc))p->foo();
if (const X* p = xtl::subtype_dynamic_cast<const X*>(px)) p->foo();
if (const Y* p = xtl::subtype_dynamic_cast<const Y*>(py)) p->foo();
if (const Z* p = xtl::subtype_dynamic_cast<const Z*>(pz)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pdc))p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pdb))p->foo();
if (const A* p = xtl::subtype_dynamic_cast<const A*>(pa)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pb)) p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pc)) p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pdb))p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pdc))p->foo();
if (const X* p = xtl::subtype_dynamic_cast<const X*>(px)) p->foo();
if (const Y* p = xtl::subtype_dynamic_cast<const Y*>(py)) p->foo();
if (const Z* p = xtl::subtype_dynamic_cast<const Z*>(pz)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pdc))p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pdb))p->foo();
}
static_assert(xtl::is_subtype<B,A>::value,"Subclassing");
}
//----------------------------------------------------------------------------------------------------------------------
// The following is also an attempt to handle tagged classes via XTL
struct Shape
{
enum Kind { KUnknown, KRectangle, KEllipse, KTriangle } kind;
static const Kind class_kind = KUnknown;
Shape(Kind k = KUnknown) : kind(k) {}
virtual void foo() { std::cout << "Shape" << std::endl; }
virtual void foo() const { std::cout << "const Shape" << std::endl; }
};
struct Rectange : Shape { static const Kind class_kind = KRectangle; Rectange() : Shape(KRectangle) {} virtual void foo() { std::cout << "Rectangle" << std::endl; } virtual void foo() const { std::cout << "const Rectangle" << std::endl; } };
struct Ellipse : Shape { static const Kind class_kind = KEllipse; Ellipse() : Shape(KEllipse) {} virtual void foo() { std::cout << "Ellipse" << std::endl; } virtual void foo() const { std::cout << "const Ellipse" << std::endl; } };
struct Triangle : Shape { static const Kind class_kind = KTriangle; Triangle() : Shape(KTriangle) {} virtual void foo() { std::cout << "Triangle" << std::endl; } virtual void foo() const { std::cout << "const Triangle" << std::endl; } };
namespace xtl
{
// Tell XTL that Shape hierarchy is XTL-polymorphic
template<>
struct is_poly_morphic<Shape>
{
static const bool value = true;
};
// Explains to XTL how to perform a subtype dynamic cast on a shape
template <class T>
typename std::enable_if<xtl::is_subtype<T, Shape>::value && !std::is_same<T, Shape>::value, T*>::type
subtype_dynamic_cast_impl(target<T*>, Shape* pv)
{
return T::class_kind == pv->kind ? static_cast<T*>(pv) : nullptr;
}
} // of namespace xtl
/// Checks tagged classes can be expressed withing the XTL approach as well
void test_shape_subtyping()
{
typedef Shape A;
typedef Rectange B;
typedef Ellipse C;
typedef Triangle D;
A a; const A ca;
B b; const B cb;
a = xtl::subtype_cast<A>(b);
a = xtl::subtype_cast<A>(cb);
//b = xtl::subtype_cast<B>(a); // error
A* qa = xtl::subtype_cast<A*>(&b);
const A* qaa= xtl::subtype_cast<const A*>(&cb); XTL_UNUSED(qaa);
//B* qb = xtl::subtype_cast<B*>(&a); // error
B* qb = xtl::subtype_dynamic_cast<B*>(qa);
qa->foo();
if (qb) qb->foo();
std::cout << "===========" << std::endl;
{
A* pA = new A;
B* pB = new B;
C* pC = new C;
D* pD = new D;
A* pa = xtl::subtype_cast<A*>(pA);
A* pb = xtl::subtype_cast<A*>(pB);
A* pc = xtl::subtype_cast<A*>(pC);
A* pd = xtl::subtype_cast<A*>(pD);
if (A* p = xtl::subtype_dynamic_cast<A*>(pa)) p->foo();
if (B* p = xtl::subtype_dynamic_cast<B*>(pb)) p->foo();
if (C* p = xtl::subtype_dynamic_cast<C*>(pc)) p->foo();
if (D* p = xtl::subtype_dynamic_cast<D*>(pd)) p->foo();
if (const A* p = xtl::subtype_dynamic_cast<const A*>(pa)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pb)) p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pc)) p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pd)) p->foo();
}
{
const A* pA = new A;
const B* pB = new B;
const C* pC = new C;
const D* pD = new D;
const A* pa = xtl::subtype_cast<const A*>(pA);
const A* pb = xtl::subtype_cast<const A*>(pB);
const A* pc = xtl::subtype_cast<const A*>(pC);
const A* pd = xtl::subtype_cast<const A*>(pD);
if (const A* p = xtl::subtype_dynamic_cast<const A*>(pa)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pb)) p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pc)) p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pd)) p->foo();
if (const A* p = xtl::subtype_dynamic_cast<const A*>(pa)) p->foo();
if (const B* p = xtl::subtype_dynamic_cast<const B*>(pb)) p->foo();
if (const C* p = xtl::subtype_dynamic_cast<const C*>(pc)) p->foo();
if (const D* p = xtl::subtype_dynamic_cast<const D*>(pd)) p->foo();
}
static_assert(xtl::is_subtype<B,A>::value,"Subclassing");
const Shape* shapes[8] = {new Shape, new Rectange, new Ellipse, new Triangle,
new Shape, new Rectange, new Ellipse, new Triangle};
for (int i = 0; i < 8; ++i)
{
Match(shapes[i])
{
Case(mch::C<Triangle>()) std::cout << "Triangle: " << std::endl; break;
Case(mch::C<Ellipse> ()) std::cout << "Ellipse: " << std::endl; break;
Case(mch::C<Rectange>()) std::cout << "Rectange: " << std::endl; break;
Case(mch::C<Shape>() ) std::cout << "Shape: " << std::endl; break;
}
EndMatch
}
}
int main()
{
test_subtype_dynamic_cast();
test_variant_subtyping();
test_variant_mutation();
test_shape_subtyping();
}
#endif