nullable_traits.hpp

#pragma once
 
#include <type_traits>
 
#include <userver/compiler/demangle.hpp>
#include <userver/storages/postgres/exceptions.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace storages::postgres::io::traits {
 
/// @brief Metafunction to detect nullability of a type.
template <typename T>
struct IsNullable : std::false_type {};
 
template <typename T>
concept kIsNullable = IsNullable<T>::value;  // NOLINT(readability-identifier-naming)
 
template <typename T>
struct GetSetNull {
    inline static bool IsNull(const T&) { return false; }
    inline static void SetNull(T&) {
        // TODO Consider a static_assert here
        throw TypeCannotBeNull(compiler::GetTypeName<T>());
    }
    inline static void SetDefault(T& value) { value = T{}; }
};
 
}  // namespace storages::postgres::io::traits
 
USERVER_NAMESPACE_END