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| constexpr | static_vec () noexcept |
| | Value-initializes data_ during constant evaluation only.
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| constexpr void | push_back (const T &value) |
| | Appends value.
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constexpr void | clear () |
| | Removes all elements (capacity unchanged).
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| constexpr void | assign (std::size_t count, const T &value) |
| | Resizes to count copies of value.
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| constexpr void | ensure_size (std::size_t count) |
| | Ensures at least count live elements without re-filling or shrinking.
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| constexpr std::size_t | size () const |
| | Returns the number of elements.
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| constexpr bool | empty () const |
| | Returns true if empty.
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| constexpr T & | operator[] (std::size_t i) |
| | Returns reference to the element at i.
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| constexpr const T & | operator[] (std::size_t i) const |
| | Returns const reference to the element at i.
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| constexpr T & | back () |
| | Returns reference to the last element. Precondition: the vector is non-empty.
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constexpr void | pop_back () |
| | Removes the last element. Precondition: the vector is non-empty.
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template<typename T, std::size_t Cap>
class real::detail::static_vec< T, Cap >
Fixed-capacity vector backed by an inline array (no heap).
The subset of std::vector the Pike VM uses, for the static storage mode. Overflow cannot happen for the engine's own containers: static_storage sizes each one exactly via its measure pass, so the length_error guards are an unreachable structural safety net — kept deliberately, and never hit at run time (hence not covered by the runtime coverage report).
- Template Parameters
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| T | Element type. |
| Cap | Inline capacity. |
template<typename T , std::size_t Cap>
Value-initializes data_ during constant evaluation only.
MSVC's constant evaluator refuses an object with an indeterminate subobject even when nothing reads it: static_regex's compile-time static_asserts failed with C2131 (expression did not evaluate to a constant) when this storage was left trivially initialized everywhere. clang and gcc accept it (C++20 P1331R2), so the runtime path — where the whole point is not paying for the clear — keeps the trivial initialization on every toolchain.
template<typename T , std::size_t Cap>
Inline element storage, deliberately NOT value-initialized at run time.
static_regex is stateless (sizeof 1), so a search() builds a fresh state on the stack every call, and value-initializing here zeroed the whole worst-case capacity each time – a cost the dynamic storage does not pay, since its state lives in the regex object and is reused. Nothing reads above size_, which starts at 0, so the zeros were never observed. C++20 permits the trivial default initialization even in a constant expression (P1331R2); reading an element before writing it would be diagnosed there rather than silently returning garbage.
On a short subject this is most of the cost of a search: the clear is proportional to the worst-case capacity while the work is proportional to the subject.
1.9.8