V8 API Reference Guide for node.js v9.8.0
Public Member Functions | Friends | List of all members
v8::Maybe< T > Class Template Reference

#include <v8.h>

Public Member Functions

V8_INLINE bool IsNothing () const
 
V8_INLINE bool IsJust () const
 
V8_INLINE T ToChecked () const
 
V8_WARN_UNUSED_RESULT V8_INLINE bool To (T *out) const
 
V8_INLINE T FromJust () const
 
V8_INLINE T FromMaybe (const T &default_value) const
 
V8_INLINE bool operator== (const Maybe &other) const
 
V8_INLINE bool operator!= (const Maybe &other) const
 

Friends

template<class U >
Maybe< U > Nothing ()
 
template<class U >
Maybe< U > Just (const U &u)
 

Detailed Description

template<class T>
class v8::Maybe< T >

A simple Maybe type, representing an object which may or may not have a value, see https://hackage.haskell.org/package/base/docs/Data-Maybe.html.

If an API method returns a Maybe<>, the API method can potentially fail either because an exception is thrown, or because an exception is pending, e.g. because a previous API call threw an exception that hasn't been caught yet, or because a TerminateExecution exception was thrown. In that case, a "Nothing" value is returned.

Member Function Documentation

template<class T>
V8_INLINE T v8::Maybe< T >::FromJust ( ) const
inline

Converts this Maybe<> to a value of type T. If this Maybe<> is nothing (empty), V8 will crash the process.

template<class T>
V8_INLINE T v8::Maybe< T >::FromMaybe ( const T &  default_value) const
inline

Converts this Maybe<> to a value of type T, using a default value if this Maybe<> is nothing (empty).

template<class T>
V8_WARN_UNUSED_RESULT V8_INLINE bool v8::Maybe< T >::To ( T *  out) const
inline

Converts this Maybe<> to a value of type T. If this Maybe<> is nothing (empty), |false| is returned and |out| is left untouched.

template<class T>
V8_INLINE T v8::Maybe< T >::ToChecked ( ) const
inline

An alias for |FromJust|. Will crash if the Maybe<> is nothing.


The documentation for this class was generated from the following file: