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🐛 Fix dynamic span construct from array #235

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Merged
merged 1 commit into from
Jun 4, 2025
Merged

🐛 Fix dynamic span construct from array #235

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7 changes: 4 additions & 3 deletions include/stdx/span.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -98,15 +98,15 @@ class span : public detail::span_base<T, Extent> {
template <typename U, std::size_t N>
// NOLINTNEXTLINE(google-explicit-constructor)
constexpr span(std::array<U, N> &arr LIFETIMEBOUND) noexcept
: ptr{std::data(arr)} {
: base_t{std::data(arr), N}, ptr{std::data(arr)} {
static_assert(Extent == dynamic_extent or Extent <= N,
"Span extends beyond available storage");
}

template <typename U, std::size_t N>
// NOLINTNEXTLINE(google-explicit-constructor)
constexpr span(std::array<U, N> const &arr LIFETIMEBOUND) noexcept
: ptr{std::data(arr)} {
: base_t{std::data(arr), N}, ptr{std::data(arr)} {
static_assert(Extent == dynamic_extent or Extent <= N,
"Span extends beyond available storage");
}
Expand All @@ -116,7 +116,8 @@ class span : public detail::span_base<T, Extent> {

template <std::size_t N>
// NOLINTNEXTLINE(google-explicit-constructor)
constexpr span(arr_t<N> arr LIFETIMEBOUND) noexcept : ptr{std::data(arr)} {
constexpr span(arr_t<N> arr LIFETIMEBOUND) noexcept
: base_t{std::data(arr), N}, ptr{std::data(arr)} {
static_assert(Extent == dynamic_extent or Extent <= N,
"Span extends beyond available storage");
}
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32 changes: 32 additions & 0 deletions test/span.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -141,6 +141,22 @@ TEST_CASE("span is constructible from std::array (non const data)", "[span]") {
STATIC_REQUIRE(std::size(s) == 4);
}

TEST_CASE("dynamic span is constructible from std::array (const data)",
"[span]") {
constexpr static auto a = std::array{1, 2, 3, 4};
auto s = [](stdx::span<int const> x) { return x; }(a);
CHECK(std::data(s) == std::data(a));
CHECK(std::size(s) == std::size(a));
}

TEST_CASE("dynamic span is constructible from std::array (non const data)",
"[span]") {
auto a = std::array{1, 2, 3, 4};
auto s = [](stdx::span<int> x) { return x; }(a);
CHECK(std::data(s) == std::data(a));
CHECK(std::size(s) == std::size(a));
}

TEST_CASE("span is constructible from C-style array (const data)", "[span]") {
constexpr static int a[] = {1, 2, 3, 4};
constexpr auto s = stdx::span{a};
Expand All @@ -159,6 +175,22 @@ TEST_CASE("span is constructible from C-style array (non const data)",
CHECK(std::size(s) == std::size(a));
}

TEST_CASE("dynamic span is constructible from C-style array (const data)",
"[span]") {
constexpr static int a[] = {1, 2, 3, 4};
auto s = [](stdx::span<int const> x) { return x; }(a);
CHECK(std::data(s) == std::data(a));
CHECK(std::size(s) == std::size(a));
}

TEST_CASE("dynamic span is constructible from C-style array (non const data)",
"[span]") {
int a[] = {1, 2, 3, 4};
auto s = [](stdx::span<int> x) { return x; }(a);
CHECK(std::data(s) == std::data(a));
CHECK(std::size(s) == std::size(a));
}

TEST_CASE("dynamic span is implicitly constructible from range (const data)",
"[span]") {
std::vector const v{1, 2, 3, 4};
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