Function concat_str_str 

pub fn concat_str_str<T: Integer>(
    lhs: StringAVT<'_, T>,
    rhs: StringAVT<'_, T>,
) -> StringArray<T>

Concatenates corresponding string pairs from two string arrays element-wise.

Performs element-wise concatenation of strings from two StringArray sources, producing a new string array where each result string is the concatenation of the corresponding left and right input strings.

Parameters

• lhs: Left-hand string array view tuple (StringArray, offset, length)
• rhs: Right-hand string array view tuple (StringArray, offset, length)

Returns

A new StringArray<T> containing concatenated strings with proper null handling.

Null Handling

• If either input string is null, the result is null
• Output null mask reflects the union of input null positions

Performance

• Pre-computes total memory requirements to minimise allocations
• Uses unsafe unchecked access for validated indices
• Optimised for bulk string concatenation operations