MSVC has compiler warnings C4127 "conditional expression is constant" (enabled
by /W4) and C6326 "Potential comparison of a constant with another constant"
(enabled by /analyze). They're potentially useful, although they're slightly
annoying to library devs who know what they're doing. In the latest version of
the compiler, C4127 is suppressed when the compiler sees simple tests like
"if (name_of_thing)", so extracting comparison expressions into named
constants is a workaround. At the same time, using std::integral_constant
avoids C6326, which doesn't look at template arguments.
test/std/containers/sequences/vector.bool/emplace.pass.cpp
Replace 1 == 1 with true, which is the same as far as the library is concerned.
Fixes D28837.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@292432 91177308-0d34-0410-b5e6-96231b3b80d8
test/std/input.output/iostream.format/input.streams/istream.unformatted/get.pass.cpp
Add static_cast<char> because basic_istream::get() returns int_type (N4606 27.7.2.3 [istream.unformatted]/4).
test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters.arithmetic/minus1.pass.cpp
Add static_cast<char> because toupper() returns int (C11 7.4.2.2/1).
test/std/iterators/stream.iterators/ostream.iterator/ostream.iterator.ops/assign_t.pass.cpp
This test is intentionally writing doubles to ostream_iterator<int>.
It's silencing -Wliteral-conversion for Clang, so I'm adding C4244 silencing for MSVC.
test/std/language.support/support.limits/limits/numeric.limits.members/infinity.pass.cpp
Given `extern float zero;`, the expression `1./zero` has type double, which emits a truncation warning
when being passed to test<float>() taking float. The fix is to say `1.f/zero` which has type float.
test/std/numerics/complex.number/cmplx.over/arg.pass.cpp
test/std/numerics/complex.number/cmplx.over/norm.pass.cpp
These tests were constructing std::complex<double>(x, 0), emitting truncation warnings when x is long long.
Saying static_cast<double>(x) avoids this.
test/std/numerics/rand/rand.eng/rand.eng.lcong/seed_result_type.pass.cpp
This was using `int s` to construct and seed a linear_congruential_engine<T, stuff>, where T is
unsigned short/unsigned int/unsigned long/unsigned long long. That emits a truncation warning in the
unsigned short case. Because the range [0, 20) is tiny and we aren't doing anything else with the index,
we can just iterate with `T s`.
test/std/re/re.traits/value.pass.cpp
regex_traits<wchar_t>::value()'s first parameter is wchar_t (N4606 28.7 [re.traits]/13). This loop is
using int to iterate through ['g', 0xFFFF), emitting a truncation warning from int to wchar_t
(which is 16-bit for some of us). Because the bound is exclusive, we can just iterate with wchar_t.
test/std/strings/basic.string/string.cons/size_char_alloc.pass.cpp
This test is a little strange. It's trying to verify that basic_string's (InIt, InIt) range constructor
isn't confused by "N copies of C" when N and C have the same integral type. To do this, it was
testing (100, 65), but that eventually emits truncation warnings from int to char. There's a simple way
to avoid this - passing (static_cast<char>(100), static_cast<char>(65)) also exercises the disambiguation.
(And 100 is representable even when char has a signed range.)
test/std/strings/string.view/string.view.hash/string_view.pass.cpp
Add static_cast<char_type> because `'0' + i` has type int.
test/std/utilities/function.objects/bind/func.bind/func.bind.bind/nested.pass.cpp
What's more horrible than nested bind()? pow() overloads! This operator()(T a, T b) was assuming that
std::pow(a, b) can be returned as T. (In this case, T is int.) However, N4606 26.9.1 [cmath.syn]/2
says that pow(int, int) returns double, so this was truncating double to int.
Adding static_cast<T> silences this.
test/std/utilities/function.objects/unord.hash/integral.pass.cpp
This was iterating `for (int i = 0; i <= 5; ++i)` and constructing `T t(i);` but that's truncating
when T is short. (And super truncating when T is bool.) Adding static_cast<T> silences this.
test/std/utilities/utility/exchange/exchange.pass.cpp
First, this was exchanging 67.2 into an int, but that's inherently truncating.
Changing this to static_cast<short>(67) avoids the truncation while preserving the
"what if T and U are different" test coverage.
Second, this was exchanging {} with the explicit type float into an int, and that's also
inherently truncating. Specifying short is just as good.
test/std/utilities/utility/pairs/pairs.spec/make_pair.pass.cpp
Add static_cast<short>. Note that this affects template argument deduction for make_pair(),
better fulfilling the test's intent. For example, this was saying
`typedef std::pair<int, short> P1; P1 p1 = std::make_pair(3, 4);` but that was asking
make_pair() to return pair<int, int>, which was then being converted to pair<int, short>.
(pair's converting constructors are tested elsewhere.)
Now, std::make_pair(3, static_cast<short>(4)) actually returns pair<int, short>.
(There's still a conversion from pair<nullptr_t, short> to pair<unique_ptr<int>, short>.)
Fixes D27544.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@289111 91177308-0d34-0410-b5e6-96231b3b80d8
