value()

std::optional< CompositeValue > MayaFlux::Kakshya::Composite::value ( std::string_view  field_name ) const

noexcept

Borrow a dynamic value; an absent field returns std::nullopt.

Definition at line 396 of file Composite.cpp.

{
    const auto field_index = m_layout->find_field(field_name);
    if (!field_index || !has(field_name)
        || m_layout->fields()[*field_index].type != typeid(detail::CompositeDynamic))
        return std::nullopt;
 
    const auto& rows = std::get<std::vector<uint8_t>>(*m_rows);
    DynamicCell cell;
    std::memcpy(&cell, rows.data() + m_index * m_layout->stride_bytes()
            + m_layout->fields()[*field_index].offset_bytes, sizeof(cell));
    if (cell.kind == null_kind)
        return CompositeValue { std::monostate {} };
    if (cell.kind == integer_kind) {
        int64_t result;
        std::memcpy(&result, &cell.payload, sizeof(result));
        return CompositeValue { result };
    }
    if (cell.kind == real_kind) {
        double result;
        std::memcpy(&result, &cell.payload, sizeof(result));
        return CompositeValue { result };
    }
    if (cell.kind == text_kind) {
        if (auto result = text(field_name))
            return CompositeValue { *result };
    }
    if (cell.kind == blob_kind) {
        if (auto result = blob(field_name))
            return CompositeValue { *result };
    }
    return std::nullopt;
}

References rows.