optional.h File Reference

Container to hold optional data. More...

#include <iostream>
#include <string>
#include <utility>
#include <algorithm>
#include "./base.h"
#include "./common.h"
#include "./logging.h"
#include "./type_traits.h"

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Classes
struct	dmlc::nullopt_t
	dummy type for assign null to optional More...
class	dmlc::optional< T >
	c++17 compatible optional class. More...
struct	std::hash< dmlc::optional< T > >
	std hash function for optional More...

Namespaces
	dmlc
	namespace for dmlc
	std

Functions
template<typename T >
std::ostream &	dmlc::operator<< (std::ostream &os, const optional< T > &t)
	serialize an optional object to string. More...
template<typename T >
std::istream &	dmlc::operator>> (std::istream &is, optional< T > &t)
	parse a string object into optional<T> More...
std::istream &	dmlc::operator>> (std::istream &is, optional< bool > &t)
	specialization of '>>' istream parsing for optional<bool> More...
	dmlc::DMLC_DECLARE_TYPE_NAME (optional< int >,"int or None")
	description for optional int More...
	dmlc::DMLC_DECLARE_TYPE_NAME (optional< bool >,"boolean or None")
	description for optional bool More...
	dmlc::DMLC_DECLARE_TYPE_NAME (optional< float >,"float or None")
	description for optional float More...
	dmlc::DMLC_DECLARE_TYPE_NAME (optional< double >,"double or None")
	description for optional double More...

Variables
constexpr const nullopt_t	dmlc::nullopt = nullopt_t(0)

Detailed Description

Container to hold optional data.

Copyright (c) 2016 by Contributors