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Do not rely on the predicate providing result_type in Filtered_predicate

This commit is contained in:
Mael Rouxel-Labbé 2024-12-20 16:15:12 +01:00
parent 9c517a47a2
commit c22fadaa32
1 changed files with 26 additions and 23 deletions
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49
Filtered_kernel/include/CGAL/Filtered_predicate.h
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@ -28,7 +28,7 @@ namespace CGAL {
// TODO :
// - each predicate in the default kernel should define a tag that says if it
// wants to be filtered or not (=> all homogeneous predicate define this
// wants to be filtered or not (=> all homogeneous predicates define this
// tag). We could even test-suite that automatically. It makes a strong
// new requirement on the kernel though...
// Could be done with a traits mechanism ?
@ -52,18 +52,13 @@ class Filtered_predicate
EP ep;
AP ap;
typedef typename AP::result_type Ares;
public:
// AP's result type must be convertible to EP's result type.
typedef AP Approximate_predicate;
typedef EP Exact_predicate;
typedef C2E To_exact_converter;
typedef C2A To_approximate_converter;
typedef typename EP::result_type result_type;
// AP::result_type must be convertible to EP::result_type.
Filtered_predicate()
{}
@ -85,11 +80,14 @@ public:
{}
template <typename... Args>
result_type
auto
operator()(const Args&... args) const
{
typedef typename Remove_needs_FT<CGAL::cpp20::remove_cvref_t<decltype(ep(c2e(args)...))> >::Type result_type;
#ifndef CGAL_EPICK_NO_INTERVALS
typedef typename Remove_needs_FT<CGAL::cpp20::remove_cvref_t<decltype(ap(c2a(args)...))> >::Type Ares;
CGAL_BRANCH_PROFILER(std::string(" failures/calls to : ") + std::string(CGAL_PRETTY_FUNCTION), tmp);
// Protection is outside the try block as VC8 has the CGAL_CFG_FPU_ROUNDING_MODE_UNWINDING_VC_BUG
{
@ -98,7 +96,7 @@ public:
{
Ares res = ap(c2a(args)...);
if (is_certain(res))
return get_certain(res);
return result_type(get_certain(res));
}
catch (Uncertain_conversion_exception&) {}
}
@ -106,7 +104,7 @@ public:
Protect_FPU_rounding<!Protection> p(CGAL_FE_TONEAREST);
CGAL_expensive_assertion(FPU_get_cw() == CGAL_FE_TONEAREST);
#endif // CGAL_EPICK_NO_INTERVALS
return ep(c2e(args)...);
return result_type(ep(c2e(args)...));
}
};
@ -120,27 +118,28 @@ class Filtered_predicate_RT_FT
EP_FT ep_ft;
AP ap;
using Ares = typename Remove_needs_FT<typename AP::result_type>::Type;
public:
using result_type = typename Remove_needs_FT<typename EP_FT::result_type>::Type;
private:
// Detect if the predicate's result type has been wrapped with the `Needs_FT` class
template <typename... Args>
struct Call_operator_needs_FT
{
using Actual_approx_res = decltype(ap(c2a(std::declval<const Args&>())...));
using Approx_res = std::remove_cv_t<std::remove_reference_t<Actual_approx_res> >;
enum { value = std::is_same<Approx_res, Needs_FT<Ares> >::value };
template <typename T>
struct is_Needs_FT : std::false_type { };
template <typename ...T>
struct is_Needs_FT<Needs_FT<T...> > : std::true_type { };
typedef CGAL::cpp20::remove_cvref_t<decltype(ap(c2a(std::declval<const Args&>())...))> Actual_approx_res;
enum { value = is_Needs_FT<Actual_approx_res>::value };
};
// If there is no `Needs_FT` in the result, then we can use an RT-based exact predicate
template <typename... Args,
std::enable_if_t<Call_operator_needs_FT<Args...>::value>* = nullptr>
result_type call(const Args&... args) const { return ep_ft(c2e_ft(args)...); }
decltype(auto) exact_call(const Args&... args) const { return ep_ft(c2e_ft(args)...); }
template <typename... Args,
std::enable_if_t<! Call_operator_needs_FT<Args...>::value>* = nullptr>
result_type call(const Args&... args) const { return ep_rt(c2e_rt(args)...); }
decltype(auto) exact_call(const Args&... args) const { return ep_rt(c2e_rt(args)...); }
public:
// ## Important note
@ -154,10 +153,14 @@ public:
bool needs_FT(const Args&...) const { return Call_operator_needs_FT<Args...>::value; }
template <typename... Args>
result_type
auto
operator()(const Args&... args) const
{
typedef typename Remove_needs_FT<CGAL::cpp20::remove_cvref_t<decltype(exact_call(args...))> >::Type result_type;
#ifndef CGAL_EPICK_NO_INTERVALS
typedef typename Remove_needs_FT<CGAL::cpp20::remove_cvref_t<decltype(ap(c2a(args)...))> >::Type Ares;
CGAL_BRANCH_PROFILER(std::string(" failures/calls to : ") + std::string(CGAL_PRETTY_FUNCTION), tmp);
// Protection is outside the try block as VC8 has the CGAL_CFG_FPU_ROUNDING_MODE_UNWINDING_VC_BUG
{
@ -166,7 +169,7 @@ public:
{
Ares res = ap(c2a(args)...);
if (is_certain(res))
return get_certain(res);
return result_type(get_certain(res));
}
catch (Uncertain_conversion_exception&) {}
}
@ -174,7 +177,7 @@ public:
Protect_FPU_rounding<!Protection> p(CGAL_FE_TONEAREST);
CGAL_expensive_assertion(FPU_get_cw() == CGAL_FE_TONEAREST);
#endif // CGAL_EPICK_NO_INTERVALS
return call(args...);
return result_type(exact_call(args...));
}
};