diff options
author | bungeman <bungeman@google.com> | 2016-03-18 11:53:16 -0700 |
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committer | Commit bot <commit-bot@chromium.org> | 2016-03-18 11:53:17 -0700 |
commit | 89edf7a95ea694ba2c0a33adedf553c4183cdc19 (patch) | |
tree | 6dd865d3de54c759716c768ece94760a82b979a3 /include/private/SkTFitsIn.h | |
parent | 8bea8905e406fc1d15ef5a8294a735f3d33fb2d0 (diff) |
Revert of Templatize SkToXXX. (patchset #2 id:20001 of https://codereview.chromium.org/1814153003/ )
Reason for revert:
Chrome does not yet have std::underlying_type.
Original issue's description:
> Templatize SkToXXX.
>
> Makes the checked cast in debug more correct, avoiding new
> warnings in vs2015.
>
> BUG=skia:4553
>
> Committed: https://skia.googlesource.com/skia/+/0be9e806af72b3e029e691eef5c891c90d3fd320
TBR=reed@google.com,mtklein@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4553
Review URL: https://codereview.chromium.org/1820433002
Diffstat (limited to 'include/private/SkTFitsIn.h')
-rw-r--r-- | include/private/SkTFitsIn.h | 227 |
1 files changed, 0 insertions, 227 deletions
diff --git a/include/private/SkTFitsIn.h b/include/private/SkTFitsIn.h deleted file mode 100644 index 4802aff1eb..0000000000 --- a/include/private/SkTFitsIn.h +++ /dev/null @@ -1,227 +0,0 @@ -/* - * Copyright 2013 Google Inc. - * - * Use of this source code is governed by a BSD-style license that can be - * found in the LICENSE file. - */ - -#ifndef SkTFitsIn_DEFINED -#define SkTFitsIn_DEFINED - -#include "../private/SkTLogic.h" -#include <limits> -#include <type_traits> - -namespace sktfitsin { -namespace Private { - -/** SkTMux::type = (a && b) ? Both : (a) ? A : (b) ? B : Neither; */ -template <bool a, bool b, typename Both, typename A, typename B, typename Neither> -struct SkTMux { - using type = skstd::conditional_t<a, skstd::conditional_t<b, Both, A>, - skstd::conditional_t<b, B, Neither>>; -}; - -/** SkTHasMoreDigits = (digits(A) >= digits(B)) ? true_type : false_type. */ -template <typename A, typename B> struct SkTHasMoreDigits - : skstd::bool_constant<std::numeric_limits<A>::digits >= std::numeric_limits<B>::digits> -{ }; - -/** A high or low side predicate which is used when it is statically known - * that source values are in the range of the Destination. - */ -template <typename S> struct SkTOutOfRange_False { - using can_be_true = std::false_type; - using source_type = S; - static bool apply(S) { - return false; - } -}; - -/** A low side predicate which tests if the source value < Min(D). - * Assumes that Min(S) <= Min(D). - */ -template <typename D, typename S> struct SkTOutOfRange_LT_MinD { - using can_be_true = std::true_type; - using source_type = S; - static bool apply(S s) { - using precondition = SkTHasMoreDigits<S, D>; - static_assert(precondition::value, "minS > minD"); - - return s < static_cast<S>((std::numeric_limits<D>::min)()); - } -}; - -/** A low side predicate which tests if the source value is less than 0. */ -template <typename D, typename S> struct SkTOutOfRange_LT_Zero { - using can_be_true = std::true_type; - using source_type = S; - static bool apply(S s) { - return s < static_cast<S>(0); - } -}; - -/** A high side predicate which tests if the source value > Max(D). - * Assumes that Max(S) >= Max(D). - */ -template <typename D, typename S> struct SkTOutOfRange_GT_MaxD { - using can_be_true = std::true_type; - using source_type = S; - static bool apply(S s) { - using precondition = SkTHasMoreDigits<S, D>; - static_assert(precondition::value, "maxS < maxD"); - - return s > static_cast<S>((std::numeric_limits<D>::max)()); - } -}; - -/** Composes two SkTOutOfRange predicates. - * First checks OutOfRange_Low then, if in range, OutOfRange_High. - */ -template <typename OutOfRange_Low, typename OutOfRange_High> struct SkTOutOfRange_Either { - using can_be_true = std::true_type; - using source_type = typename OutOfRange_Low::source_type; - static bool apply(source_type s) { - bool outOfRange = OutOfRange_Low::apply(s); - if (!outOfRange) { - outOfRange = OutOfRange_High::apply(s); - } - return outOfRange; - } -}; - -/** SkTCombineOutOfRange::type is an SkTOutOfRange_XXX type which is the - * optimal combination of OutOfRange_Low and OutOfRange_High. - */ -template <typename OutOfRange_Low, typename OutOfRange_High> struct SkTCombineOutOfRange { - using Both = SkTOutOfRange_Either<OutOfRange_Low, OutOfRange_High>; - using Neither = SkTOutOfRange_False<typename OutOfRange_Low::source_type>; - - using apply_low = typename OutOfRange_Low::can_be_true; - using apply_high = typename OutOfRange_High::can_be_true; - - using type = typename SkTMux<apply_low::value, apply_high::value, - Both, OutOfRange_Low, OutOfRange_High, Neither>::type; -}; - -template <typename D, typename S, typename OutOfRange_Low, typename OutOfRange_High> -struct SkTRangeChecker { - /** This is the method which is called at runtime to do the range check. */ - static bool OutOfRange(S s) { - using Combined = typename SkTCombineOutOfRange<OutOfRange_Low, OutOfRange_High>::type; - return Combined::apply(s); - } -}; - -/** SkTFitsIn_Unsigned2Unsiged::type is an SkTRangeChecker with an OutOfRange(S s) method - * the implementation of which is tailored for the source and destination types. - * Assumes that S and D are unsigned integer types. - */ -template <typename D, typename S> struct SkTFitsIn_Unsigned2Unsiged { - using OutOfRange_Low = SkTOutOfRange_False<S>; - using OutOfRange_High = SkTOutOfRange_GT_MaxD<D, S>; - - using HighSideOnlyCheck = SkTRangeChecker<D, S, OutOfRange_Low, OutOfRange_High>; - using NoCheck = SkTRangeChecker<D, S, SkTOutOfRange_False<S>, SkTOutOfRange_False<S>>; - - // If std::numeric_limits<D>::digits >= std::numeric_limits<S>::digits, nothing to check. - // This also protects the precondition of SkTOutOfRange_GT_MaxD. - using sourceFitsInDesitination = SkTHasMoreDigits<D, S>; - using type = skstd::conditional_t<sourceFitsInDesitination::value, NoCheck, HighSideOnlyCheck>; -}; - -/** SkTFitsIn_Signed2Signed::type is an SkTRangeChecker with an OutOfRange(S s) method - * the implementation of which is tailored for the source and destination types. - * Assumes that S and D are signed integer types. - */ -template <typename D, typename S> struct SkTFitsIn_Signed2Signed { - using OutOfRange_Low = SkTOutOfRange_LT_MinD<D, S>; - using OutOfRange_High = SkTOutOfRange_GT_MaxD<D, S>; - - using FullCheck = SkTRangeChecker<D, S, OutOfRange_Low, OutOfRange_High>; - using NoCheck = SkTRangeChecker<D, S, SkTOutOfRange_False<S>, SkTOutOfRange_False<S>>; - - // If std::numeric_limits<D>::digits >= std::numeric_limits<S>::digits, nothing to check. - // This also protects the precondition of SkTOutOfRange_LT_MinD and SkTOutOfRange_GT_MaxD. - using sourceFitsInDesitination = SkTHasMoreDigits<D, S>; - using type = skstd::conditional_t<sourceFitsInDesitination::value, NoCheck, FullCheck>; -}; - -/** SkTFitsIn_Signed2Unsigned::type is an SkTRangeChecker with an OutOfRange(S s) method - * the implementation of which is tailored for the source and destination types. - * Assumes that S is a signed integer type and D is an unsigned integer type. - */ -template <typename D, typename S> struct SkTFitsIn_Signed2Unsigned { - using OutOfRange_Low = SkTOutOfRange_LT_Zero<D, S>; - using OutOfRange_High = SkTOutOfRange_GT_MaxD<D, S>; - - using FullCheck = SkTRangeChecker<D, S, OutOfRange_Low, OutOfRange_High>; - using LowSideOnlyCheck = SkTRangeChecker<D, S, OutOfRange_Low, SkTOutOfRange_False<S>>; - - // If std::numeric_limits<D>::max() >= std::numeric_limits<S>::max(), - // no need to check the high side. (Until C++11, assume more digits means greater max.) - // This also protects the precondition of SkTOutOfRange_GT_MaxD. - using sourceCannotExceedDest = SkTHasMoreDigits<D, S>; - using type = skstd::conditional_t<sourceCannotExceedDest::value, LowSideOnlyCheck, FullCheck>; -}; - -/** SkTFitsIn_Unsigned2Signed::type is an SkTRangeChecker with an OutOfRange(S s) method - * the implementation of which is tailored for the source and destination types. - * Assumes that S is an usigned integer type and D is a signed integer type. - */ -template <typename D, typename S> struct SkTFitsIn_Unsigned2Signed { - using OutOfRange_Low = SkTOutOfRange_False<S>; - using OutOfRange_High = SkTOutOfRange_GT_MaxD<D, S>; - - using HighSideOnlyCheck = SkTRangeChecker<D, S, OutOfRange_Low, OutOfRange_High>; - using NoCheck = SkTRangeChecker<D, S, SkTOutOfRange_False<S>, SkTOutOfRange_False<S>>; - - // If std::numeric_limits<D>::max() >= std::numeric_limits<S>::max(), nothing to check. - // (Until C++11, assume more digits means greater max.) - // This also protects the precondition of SkTOutOfRange_GT_MaxD. - using sourceCannotExceedDest = SkTHasMoreDigits<D, S>; - using type = skstd::conditional_t<sourceCannotExceedDest::value, NoCheck, HighSideOnlyCheck>; -}; - -/** SkTFitsIn::type is an SkTRangeChecker with an OutOfRange(S s) method - * the implementation of which is tailored for the source and destination types. - * Assumes that S and D are integer types. - */ -template <typename D, typename S> struct SkTFitsIn { - // One of the following will be the 'selector' type. - using S2S = SkTFitsIn_Signed2Signed<D, S>; - using S2U = SkTFitsIn_Signed2Unsigned<D, S>; - using U2S = SkTFitsIn_Unsigned2Signed<D, S>; - using U2U = SkTFitsIn_Unsigned2Unsiged<D, S>; - - using S_is_signed = skstd::bool_constant<std::numeric_limits<S>::is_signed>; - using D_is_signed = skstd::bool_constant<std::numeric_limits<D>::is_signed>; - - using selector = typename SkTMux<S_is_signed::value, D_is_signed::value, - S2S, S2U, U2S, U2U>::type; - // This type is an SkTRangeChecker. - using type = typename selector::type; -}; - -template <typename T, bool = std::is_enum<T>::value> struct underlying_type { - using type = skstd::underlying_type_t<T>; -}; -template <typename T> struct underlying_type<T, false> { - using type = T; -}; - -} // namespace Private -} // namespace sktfitsin - -/** Returns true if the integer source value 's' will fit in the integer destination type 'D'. */ -template <typename D, typename S> inline bool SkTFitsIn(S s) { - static_assert(std::is_integral<S>::value || std::is_enum<S>::value, "S must be integral."); - static_assert(std::is_integral<D>::value || std::is_enum<D>::value, "D must be integral."); - - using RealS = typename sktfitsin::Private::underlying_type<S>::type; - using RealD = typename sktfitsin::Private::underlying_type<D>::type; - - return !sktfitsin::Private::SkTFitsIn<RealD, RealS>::type::OutOfRange(s); -} - -#endif |