ClickHouse/src/Core/iostream_debug_helpers.h
Robert Schulze b56c28d841
Replace a few uses of enable_if for SFINAE by concepts
- enable_if is usually regarded as fragile and unreadable

- C++20 concepts are much easier to read and produce more expressive
  error messages
2022-03-16 19:51:38 +01:00

50 lines
1.5 KiB
C++

#pragma once
#include <iostream>
namespace DB
{
// Use template to disable implicit casting for certain overloaded types such as Field, which leads
// to overload resolution ambiguity.
class Field;
template <typename T>
requires std::is_same_v<T, Field>
std::ostream & operator<<(std::ostream & stream, const T & what);
struct NameAndTypePair;
std::ostream & operator<<(std::ostream & stream, const NameAndTypePair & what);
class IDataType;
std::ostream & operator<<(std::ostream & stream, const IDataType & what);
class IStorage;
std::ostream & operator<<(std::ostream & stream, const IStorage & what);
class IFunctionOverloadResolver;
std::ostream & operator<<(std::ostream & stream, const IFunctionOverloadResolver & what);
class IFunctionBase;
std::ostream & operator<<(std::ostream & stream, const IFunctionBase & what);
class Block;
std::ostream & operator<<(std::ostream & stream, const Block & what);
struct ColumnWithTypeAndName;
std::ostream & operator<<(std::ostream & stream, const ColumnWithTypeAndName & what);
class IColumn;
std::ostream & operator<<(std::ostream & stream, const IColumn & what);
struct Packet;
std::ostream & operator<<(std::ostream & stream, const Packet & what);
class ExpressionActions;
std::ostream & operator<<(std::ostream & stream, const ExpressionActions & what);
struct TreeRewriterResult;
std::ostream & operator<<(std::ostream & stream, const TreeRewriterResult & what);
}
/// some operator<< should be declared before operator<<(... std::shared_ptr<>)
#include <base/iostream_debug_helpers.h>