Fove::Result< Value > Class Template Reference

Class for return values from the C++ API. More...

#include <FoveAPI.h>

Public Member Functions
	Result ()=default
	Constructs a result with a default-initialized value.
	Result (const ErrorCode err)
	Constructs a result with an error.
	Result (const Value &data)
	Constructs a result with a value.
	Result (Value &&data)
	Move constructor.
ErrorCode	getError () const
	Returns the error code.
Value &	getValue () &
	Returns the value if isValid() is true, otherwise throws.
Value &&	getValue () &&
	Returns the value if isValid() is true, otherwise throws.
const Value &	getValue () const &
	Returns the value if isValid() is true, otherwise throws.
const Value &	getValueUnchecked () const
	Returns the value without checking the error field. More...
bool	isValid () const
	Returns true if there is no error.
	operator bool () const
	Explicit conversion to bool, for use in if statements.
Value &	operator* ()
	Pointer-like semantics to fetch value, throws if invalid.
Value const &	operator* () const
	Pointer-like semantics to fetch value, throws if invalid.
Value *	operator-> ()
	Pointer-like semantics to fetch value, throws if invalid.
Value const *	operator-> () const
	Pointer-like semantics to fetch value, throws if invalid.
void	throwIfInvalid () const
	Throws if there is an error, otherwise is a no-op. More...
Value	valueOr (Value defValue) const
	Returns the value if available, otherwise returns the provided default. More...

Static Public Member Functions
template<typename Call , typename... Args>
static Result	invoke (Call *call, const Args... args)
	Helper function to create an error by calling a C API function.
template<typename Call , typename... Args>
static Result	invokeStereo (Call *call, const Args... args)
	Variant of invoke for functions that have a left and a right output.

Detailed Description

template<typename Value = std::nullptr_t>
class Fove::Result< Value >

Class for return values from the C++ API.

This class represents either an error or a value, similar to std::variant<ErrorCode, Value> but without including C++17 The there is an error and the value is requested, an exception will be thrown.

nullptr_t is a special type that indicates "no value", just an error field.

Member Function Documentation

getValueUnchecked()

template<typename Value = std::nullptr_t>

const Value& Fove::Result< Value >::getValueUnchecked

(

)

const

Returns the value without checking the error field.

It is expected that the error was checked manually before calling this field, for example via throwIfInvalid(). The return value is undefined if isValid() is false.

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throwIfInvalid()

template<typename Value = std::nullptr_t>

void Fove::Result< Value >::throwIfInvalid

(

)

const

Throws if there is an error, otherwise is a no-op.

If exceptions are disabled, this will terminate the program instead of throwing.

valueOr()

template<typename Value = std::nullptr_t>

Value Fove::Result< Value >::valueOr

(

Value

defValue

)

const

Returns the value if available, otherwise returns the provided default.

Parameters

defValue

A value to return if this object is not valid