io_fwd.hpp

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#pragma once
 
/// @file userver/storages/clickhouse/io/io_fwd.hpp
/// @brief Customization point for Ch driver C++ <-> ClickHouse mappings.
 
USERVER_NAMESPACE_BEGIN
 
namespace storages::clickhouse::io {
 
// clang-format off
/// @page clickhouse_io
///
/// uClickHouse driver doesn't expose underlying ClickHouse types and only provides a
/// way to convert results to strongly-typed structs/containers
/// (see storages::clickhouse::ExecutionResult).
///
/// As naive mapping is ambiguous for some types, namely for chrono and string,
/// explicit mapping is required by the driver - explicit specialization of
/// `CppToClickhouse` template.
///
/// @section types Supported Clickhouse types:
/// - DateTime @ref storages::clickhouse::io::columns::DateTimeColumn
/// - DateTime64([3, 6, 9]) @ref storages::clickhouse::io::columns::DateTime64Column
/// - Int8 @ref storages::clickhouse::io::columns::Int8Column
/// - Int32 @ref storages::clickhouse::io::columns::Int32Column
/// - Int64 @ref storages::clickhouse::io::columns::Int64Column
/// - UInt8 @ref storages::clickhouse::io::columns::UInt8Column
/// - UInt16 @ref storages::clickhouse::io::columns::UInt16Column
/// - UInt32 @ref storages::clickhouse::io::columns::UInt32Column
/// - UInt64 @ref storages::clickhouse::io::columns::UInt64Column
/// - String @ref storages::clickhouse::io::columns::StringColumn
/// - UUID @ref storages::clickhouse::io::columns::UuidColumn
/// - Nullable @ref storages::clickhouse::io::columns::NullableColumn
/// - Float32 @ref storages::clickhouse::io::columns::Float32Column
/// - Float64 @ref storages::clickhouse::io::columns::Float64Column
///
/// ## Example usage:
///
/// @snippet storages/tests/execute_chtest.cpp  Sample CppToClickhouse specialization
// clang-format on
template <typename T>
struct CppToClickhouse;
 
}  // namespace storages::clickhouse::io
 
USERVER_NAMESPACE_END