[gouarin]

Checklist

• The title and commit message(s) are descriptive.
• Small commits made to fix your PR have been squashed to avoid history pollution.
• Tests have been added for new features or bug fixes.
• API of new functions and classes are documented (no public API changes).

Description

xt::apply is declared noexcept(noexcept(func(std::get<0>(s)))), which only looks at the call on the first tuple element. The body also holds an XTENSOR_ASSERT on the index. Both cases call std::terminate instead of propagating the exception:

auto f = [](int i) noexcept { return i; };
xt::apply<int>(5, f, std::make_tuple(1, 2, 3));  // index out of range, with XTENSOR_ENABLE_ASSERT

struct g_t
{
    int operator()(int i) const noexcept { return i; }
    int operator()(const std::string&) const { throw std::runtime_error("g"); }
};
xt::apply<int>(1, g_t{}, std::make_tuple(1, std::string("a")));  // noexcept only looked at g_t{}(1)

GCC reports the first one with -Wterminate and clang with -Wexceptions in the assert builds.

The specification is now detail::is_nothrow_apply_v: the functor on every element converted to R, the R{} fallback, and the index check, through a new detail::assert_can_throw constant. xutils.hpp now includes xexception.hpp, since it uses XTENSOR_ASSERT.

utils.apply_propagates_exception and utils.apply_out_of_range terminate on master and pass with the fix. The noexcept check in utils.apply now expects false in assert builds.

[codspeed]

Merging this PR will not alter performance

1 warning

⚠️ Unable to measure the execution of 1 benchmark

This benchmark measured no execution time, so its result is not comparable and counts as unchanged. This usually happens when the compiler removes the code under test.

Prevent compiler optimizations

See affected benchmarks

✅ 255 untouched benchmarks

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_{Comparing gouarin:fix-apply-noexcept (25547ad) with master (57f3d07)}