On 14 March 2018 at 23:01, Jonathan Wakely wrote: > Here's a very different patch. This gets rid of the __ptr_rel_ops and > just puts the special handling for pointers directly in the > std::less<_Tp*> etc. specializations. Then std::less<void> uses > std::less<P*> for some pointer type P*. I've also added a ton of ugly > metaprogramming to detect the "if the call operator calls a built-in > operator comparing pointers" condition. The idea is borrowed from > Casey Carter and Eric Niebler's Ranges work, but basically it checks > if operator<(T,U) or T.operator<(U) can be called, and if not the > comparison must be using a built-in operator. If both T and U are > convertible to pointers (specifically, to const volatile void* which > is the most accepting of all pointers) then we assume we're using a > built-in operator comparing pointers, and delegate to std::less<const > volatile void*>, which ensures a total order. > > Tested powerpc64le-linux, committed to trunk. This fixes a regression, > but I'm not sure about backporting it yet, I haven't even tried > testing it on the branches.
This adjusts the new test to avoid using 'auto' so it works as C++98 too.
commit be039c0c67a6d18ddeb86bddc50cd9704a120f75 Author: Jonathan Wakely <jwak...@redhat.com> Date: Sat Mar 17 13:35:50 2018 +0000 Fix new test that fails in C++98 mode * testsuite/20_util/function_objects/comparisons_pointer.cc: Adjust to compile as C++98. diff --git a/libstdc++-v3/testsuite/20_util/function_objects/comparisons_pointer.cc b/libstdc++-v3/testsuite/20_util/function_objects/comparisons_pointer.cc index 6b2b8be0f51..aad0bc3dd2e 100644 --- a/libstdc++-v3/testsuite/20_util/function_objects/comparisons_pointer.cc +++ b/libstdc++-v3/testsuite/20_util/function_objects/comparisons_pointer.cc @@ -27,7 +27,7 @@ int a[8]; void test01() { - auto p = a + 8; + int* p = a + 8; std::greater<int*> gt; std::stringstream ss; @@ -44,7 +44,7 @@ test01() ss.str(""); ss.clear(); sum = 0; - auto p2 = a + 8; + int* p2 = a + 8; std::greater<> gt2; ss << gt2(p2, b) << ' ' << gt2(b, p2) << ' ' << (!gt2(p2, b) && !gt2(b, p2)); while (ss >> n) @@ -59,7 +59,7 @@ test01() void test02() { - auto p = a + 8; + int* p = a + 8; std::less<int*> lt; std::stringstream ss; @@ -76,7 +76,7 @@ test02() ss.str(""); ss.clear(); sum = 0; - auto p2 = a + 8; + int* p2 = a + 8; std::less<> lt2; ss << lt2(p2, b) << ' ' << lt2(b, p2) << ' ' << (!lt2(p2, b) && !lt2(b, p2)); while (ss >> n) @@ -91,7 +91,7 @@ test02() void test03() { - auto p = a + 8; + int* p = a + 8; std::greater_equal<int*> ge; std::stringstream ss; @@ -109,7 +109,7 @@ test03() ss.str(""); ss.clear(); sum = 0; - auto p2 = a + 8; + int* p2 = a + 8; std::greater_equal<> ge2; ss << !ge2(p2, b) << ' ' << !ge2(b, p2) << ' ' << (ge2(p2, b) && ge2(b, p2)); while (ss >> n) @@ -125,7 +125,7 @@ test03() void test04() { - auto p = a + 8; + int* p = a + 8; std::less_equal<int*> le; std::stringstream ss; @@ -143,7 +143,7 @@ test04() ss.str(""); ss.clear(); sum = 0; - auto p2 = a + 8; + int* p2 = a + 8; std::less_equal<> le2; ss << !le2(p2, b) << ' ' << !le2(b, p2) << ' ' << (le2(p2, b) && le2(b, p2)); while (ss >> n) @@ -167,7 +167,7 @@ void test05() { std::less<const X*> lt; - auto p = y + 4; + X* p = y + 4; std::stringstream ss; ss << lt(x, p) << ' ' << lt(p, x) << ' ' << (!lt(p, x) && !lt(x, p)); int sum = 0; @@ -183,7 +183,7 @@ test05() ss.str(""); ss.clear(); sum = 0; - auto p2 = y + 4; + X* p2 = y + 4; std::less<> lt2; ss << lt2(x, p2) << ' ' << lt2(p2, x) << ' ' << (!lt2(x, p2) && !lt2(p2, x)); while (ss >> n)