Merge pull request #603 from elbeno/field-fitting

✨ Add `can_hold` to `field`
intel · Aug 27, 2024 · 0c464e5 · 0c464e5
2 parents 924cab6 + 066e932
commit 0c464e5
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diff --git a/include/msg/field.hpp b/include/msg/field.hpp
@@ -274,6 +274,8 @@ template <bits_locator... BLs> struct field_locator_t {
  template <typename T> constexpr static auto extent_in() -> std::size_t {
  return std::max({std::size_t{}, BLs::template extent_in<T>()...});
  }
+
+ constexpr static auto size = (std::size_t{} + ... + BLs::size);
 };
 } // namespace detail
 
@@ -451,6 +453,10 @@ class field_t : public field_spec_t<Name, T, detail::field_size<Ats...>>,
  return format("{}: 0x{:x}"_sc, spec_t::name, v);
  }
 
+ constexpr static auto can_hold(value_type v) -> bool {
+ return locator_t::size >= static_cast<std::size_t>(stdx::bit_width(v));
+ }
+
  // ======================================================================
  // default construction values
  template <T V>

diff --git a/test/msg/field_insert.cpp b/test/msg/field_insert.cpp
@@ -121,3 +121,18 @@ TEST_CASE("trivially_copyable field type ", "[field insert]") {
  F::insert(data, custom_t{17});
  CHECK(17 == stdx::bit_cast<custom_t>(data[0]).v);
 }
+
+TEST_CASE("value fits in field", "[field insert]") {
+ using F = field<"", std::uint32_t>::located<at{0_dw, 3_msb, 0_lsb}>;
+ static_assert(F::can_hold(15));
+ CHECK(F::can_hold(15));
+ CHECK(not F::can_hold(16));
+}
+
+TEST_CASE("value fits in split field", "[field insert]") {
+ using F = field<"", std::uint32_t>::located<at{0_dw, 1_msb, 0_lsb},
+ at{0_dw, 7_msb, 6_lsb}>;
+ static_assert(F::can_hold(15));
+ CHECK(F::can_hold(15));
+ CHECK(not F::can_hold(16));
+}