ClickHouse/dbms/DataTypes/getMostSubtype.h

#pragma once

#include <DataTypes/IDataType.h>


namespace DB
{

/** Get data type that covers intersection of all possible values of passed data types.
  * DataTypeNothing is the most common subtype for all types.
  * Examples: most common subtype for UInt16, UInt8 and Int8 - UInt16.
  * Examples: most common subtype for Array(UInt8), Int8 is Nothing
  *
  * If force_support_conversion is true, returns type which may be used to convert each argument to.
  * Example: most common subtype for Array(UInt8) and Array(Nullable(Int32)) is Array(Nullable(UInt8) if force_support_conversion is true.
  */
DataTypePtr getMostSubtype(const DataTypes & types, bool throw_if_result_is_nothing = false, bool force_support_conversion = false);

}