libgig  4.5.0.svn7
Serialization::DataType Class Reference

Abstract reflection of a native C++ data type. More...

#include <Serialization.h>

Classes

class  NativeDataTypeRegistry
 Registrator for native data types. More...
 

Public Member Functions

 DataType ()
 Default constructor (as "invalid" DataType). More...
 
size_t size () const
 Returns native memory size of the respective C++ object or variable.
 
bool isValid () const
 Check if this is a valid DataType object. More...
 
bool isPointer () const
 Whether this is reflecting a C/C++ pointer type. More...
 
bool isClass () const
 Whether this is reflecting a C/C++ struct or class type. More...
 
bool isPrimitive () const
 Whether this is reflecting a fundamental C/C++ data type. More...
 
bool isString () const
 Whether this is a C++ String data type. More...
 
bool isInteger () const
 Whether this is an integer C/C++ data type. More...
 
bool isReal () const
 Whether this is a floating point based C/C++ data type. More...
 
bool isBool () const
 Whether this is a boolean C/C++ data type. More...
 
bool isEnum () const
 Whether this is a C/C++ enum data type. More...
 
bool isArray () const
 Whether this is a C++ Array<> object type. More...
 
bool isSet () const
 Whether this is a C++ Set<> object type. More...
 
bool isMap () const
 Whether this is a C++ Map<> object type. More...
 
bool isSigned () const
 Whether this is a signed integer C/C++ data type. More...
 
 operator bool () const
 Same as calling isValid().
 
bool operator== (const DataType &other) const
 Comparison for equalness. More...
 
bool operator!= (const DataType &other) const
 Comparison for inequalness. More...
 
bool operator< (const DataType &other) const
 Smaller than comparison. More...
 
bool operator> (const DataType &other) const
 Greater than comparison. More...
 
String asLongDescr () const
 Human readable long description for this data type. More...
 
String baseTypeName () const
 The base type name of this data type. More...
 
String customTypeName (bool demangle=false) const
 The 1st user defined C/C++ data type name of this data type. More...
 
String customTypeName2 (bool demangle=false) const
 The 2nd user defined C/C++ data type name of this data type. More...
 

Static Public Member Functions

template<typename T >
static DataType dataTypeOf (const T &data)
 Construct a DataType object for the given native C++ data. More...
 
template<typename T >
static DataType dataType ()
 Construct a DataType object for the given native C++ type. More...
 
template<typename T >
static void registerNativeDataType ()
 Manual registration of native C++ data types. More...
 

Protected Member Functions

 DataType (bool isPointer, int size, String baseType, String customType1="", String customType2="")
 Constructs a valid DataType object. More...
 
String internalID () const
 Unique key for native data type, for internal purposes only. More...
 
Object newInstance (Archive *archive) const
 Allocate and initialize a native instance of data type. More...
 

Static Protected Member Functions

template<typename T , typename std::enable_if< std::is_default_constructible< T >::value, bool >::type = true>
static void registerNativeDataType (const DataType &type, const T &nativeData)
 
template<typename T , typename std::enable_if<!std::is_default_constructible< T >::value, bool >::type = true>
static void registerNativeDataType (const DataType &type, const T &nativeData)
 
template<typename T >
static String rawCppTypeName ()
 
template<typename T >
static String rawCppTypeNameOf (const T *const &data)
 
template<typename T >
static String rawCppTypeNameOf (const T &data)
 

Detailed Description

Abstract reflection of a native C++ data type.

Provides detailed information about a serialized C++ data type, whether it is a fundamental C/C++ data type (like int, float, char, etc.) or custom defined data types like a C++ class, C/C++ struct, enum, as well as other features of the respective data type like its native memory size and more.

All informations provided by this class are retrieved from the respective individual C++ objects, their members and other data when they are serialized, and all those information are stored with the serialized archive and its resulting data stream. Due to the availability of these extensive data type information within serialized archives, this framework is capable to use them in order to adapt its deserialization process upon subsequent changes to your individual C++ classes.

Definition at line 443 of file Serialization.h.

Constructor & Destructor Documentation

◆ DataType() [1/2]

Serialization::DataType::DataType ( )

Default constructor (as "invalid" DataType).

Initializes a DataType object as being an "invalid" DataType object. Thus calling isValid(), after creating a DataType object with this constructor, would return false.

To create a valid and meaningful DataType object instead, call the static function DataType::dataTypeOf() instead.

Definition at line 96 of file Serialization.cpp.

◆ DataType() [2/2]

Serialization::DataType::DataType ( bool  isPointer,
int  size,
String  baseType,
String  customType1 = "",
String  customType2 = "" 
)
protected

Constructs a valid DataType object.

Initializes this object as "valid" DataType object, with specific and useful data type information.

This is a protected constructor which should not be called directly by applications, as its argument list is somewhat implementation specific and might change at any time. Applications should call the static function DataType::dataTypeOf() instead.

Parameters
isPointer- whether pointer type (i.e. a simple memory address)
size- native size of data type in bytes (i.e. according to sizeof() C/C++ keyword)
baseType- this framework's internal name for specifying the base type in a coarse way, which must be either one of: "int8", "uint8", "int16", "uint16", "int32", "uint32", "int64", "uint64", "bool", "real32", "real64", "String", "Array", "Set", "enum", "union" or "class"
customType1- this is only used for base types "enum", "union", "class", "Array", "Set" or "Map", in which case this identifies the user defined type name (e.g. "Foo" for class Foo or e.g. "Bar" for Array<Bar> respectively), for all other types this is empty
customType2- this is only used for Map<> objects in which case it identifies the map's value type (i.e. 2nd template parameter of map)

Definition at line 128 of file Serialization.cpp.

References isPointer(), and size().

Member Function Documentation

◆ asLongDescr()

String Serialization::DataType::asLongDescr ( ) const

Human readable long description for this data type.

Returns a human readable long description for this data type, designed for the purpose for being displayed to the user. Note that the implementation for this method and thus the precise textual strings returned by this method, may change at any time. So you should not rely on precise strings for certain data types, and you should not use the return values of this method for comparing data types with each other.

This class implements various comparison operators, so you should use them for comparing DataTypes objects instead.

See also
baseTypeName(), customTypeName()

Definition at line 467 of file Serialization.cpp.

References customTypeName(), customTypeName2(), and isPointer().

◆ baseTypeName()

String Serialization::DataType::baseTypeName ( ) const

The base type name of this data type.

Returns a textual short string identifying the basic type of name of this data type. For example for a 32 bit signed integer data type this method would return "int32". For all user defined C/C++ enum types this method would return "enum". For all user defined C/C++ struct and class types this method would return "class" for both. Note that the precise user defined type name (of i.e. enum, struct and class types) is not included in the string returned by this method, use customTypeName() to retrieve that information instead.

The precise textual strings returned by this method are guaranteed to retain equal with future versions of this framework. So you can rely on them for using the return values of this method for comparison tasks in your application. Note however that this class also implements various comparison operators.

Further it is important to know that this method returns the same string for pointers and non-pointers of the same underlying data type. So in the following example:

#include <stdint.h>
uint64_t i;
uint64_t* pi;

this method would return for both i and pi the string "uint64" !

See also
isPointer(), customTypeName(), customTypeName2()

Definition at line 507 of file Serialization.cpp.

◆ customTypeName()

String Serialization::DataType::customTypeName ( bool  demangle = false) const

The 1st user defined C/C++ data type name of this data type.

Call this method on user defined C/C++ data types like enum, struct, class or Array<> types to retrieve the user defined type name portion of those data types. Note that this method is only intended for such user defined data types. For all fundamental, primitive data types (like i.e. int) this method returns an empty string instead.

This method takes an optional boolean argument demangle, which allows you define whether you are interested in the raw C++ type name or rather the demangled custom type name. By default this method returns the raw C++ type name. The raw C++ type name is the one that is actually used in the compiled binaries and should be preferred for comparions tasks. The demangled C++ type name is a human readable representation of the type name instead, which you may use for displaying the user defined type name portion to the user, however you should not use the demangled representation for comparison tasks.

Note that in the following example:

struct Foo {
int a;
bool b;
};
Foo foo;
Foo* pFoo;

this method would return the same string for both foo and pFoo ! In the latter example customTypeName(true) would return for both foo and pFoo the string "Foo" as return value of this method.

Windows: please note that the current implementation of this method on Windows is not thread safe!

See also
baseTypeName(), customTypeName2(), isPointer()

Definition at line 570 of file Serialization.cpp.

Referenced by asLongDescr().

◆ customTypeName2()

String Serialization::DataType::customTypeName2 ( bool  demangle = false) const

The 2nd user defined C/C++ data type name of this data type.

This is currently only used for Map<> data types in which case this method returns the map's value type (i.e. map's 2nd template parameter).

See also
baseTypeName(), customTypeName()

Definition at line 582 of file Serialization.cpp.

Referenced by asLongDescr().

◆ dataType()

template<typename T >
static DataType Serialization::DataType::dataType ( )
inlinestatic

Construct a DataType object for the given native C++ type.

This methods basically behaves similar to above's method, whith the difference that above's method takes an argument to real native data and resolves its run-time type information (RTTI), whereas this version here just takes a compile-time constant template argument.

Returns
corresponding DataType object for the supplied C/C++ type
See also
dataTypeOf() for run-time variant data types

Definition at line 501 of file Serialization.h.

◆ dataTypeOf()

template<typename T >
static DataType Serialization::DataType::dataTypeOf ( const T &  data)
inlinestatic

Construct a DataType object for the given native C++ data.

Use this function to create corresponding DataType objects for native C/C++ objects, members and variables. Run-time type information (RTTI) is used to resolve its type information.

Parameters
data- native C/C++ object/member/variable a DataType object shall be created for
Returns
corresponding DataType object for the supplied native C/C++ object/member/variable
See also
dataType() for compile-time known data types

Definition at line 484 of file Serialization.h.

References registerNativeDataType().

Referenced by registerNativeDataType(), Serialization::Archive::serializeAnonymousObject(), Serialization::Archive::serializeHeapMember(), Serialization::Archive::serializeMember(), Serialization::Archive::setMinVersion(), and Serialization::Archive::setVersion().

◆ internalID()

String Serialization::DataType::internalID ( ) const
protected

Unique key for native data type, for internal purposes only.

This is more or less just a random string acting as a key for the native data type. The way this string is assembled may change at any time in future, so it is only constant for the data type during current runtime.

The generated key is used to store lambdas for each data type, e.g. for allocation and initialization of the actual native data type via the reflection API.

See also
newInstance()

Definition at line 397 of file Serialization.cpp.

References isClass().

Referenced by newInstance(), and registerNativeDataType().

◆ isArray()

bool Serialization::DataType::isArray ( ) const

Whether this is a C++ Array<> object type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a C++ Array<> container object type.

Note
: This framework handles Array<> types neither as primitive types, nor as class types. So isPrimitive() and isClass() both return false for arrays.
See also
isPointer()

Definition at line 305 of file Serialization.cpp.

Referenced by isPrimitive().

◆ isBool()

bool Serialization::DataType::isBool ( ) const

Whether this is a boolean C/C++ data type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a (fundamental, primitive) boolean data type. So this is the case for the C++ bool data type. It does not include integer or floating point types though.

Note that this method also returns true on bool pointer types!

See also
isPointer()

Definition at line 274 of file Serialization.cpp.

Referenced by Serialization::Archive::setAutoValue().

◆ isClass()

bool Serialization::DataType::isClass ( ) const

Whether this is reflecting a C/C++ struct or class type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a C/C++ struct or class type.

Note
: Data types which enjoy out of the box serialization support by this framework, like String and Array<> are NOT handled as class data types by this framwork. So isClass() returns false for e.g. String and any Array<> based data type.

Note that in the following example:

struct Foo {
int a;
bool b;
};
Foo foo;
Foo* pFoo;

the DataType objects of both foo, as well as of the C/C++ pointer pFoo would both return true for isClass() here!

See also
isPointer()

Definition at line 186 of file Serialization.cpp.

Referenced by internalID(), isPrimitive(), and operator==().

◆ isEnum()

bool Serialization::DataType::isEnum ( ) const

Whether this is a C/C++ enum data type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a user defined enumeration data type. So this is the case for all C/C++ enum data types. It does not include integer (or even floating point) types though.

Note that this method also returns true on enum pointer types!

See also
isPointer()

Definition at line 289 of file Serialization.cpp.

Referenced by Serialization::Archive::setAutoValue().

◆ isInteger()

bool Serialization::DataType::isInteger ( ) const

Whether this is an integer C/C++ data type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a (fundamental, primitive) integer data type. So these are all int and unsigned int types of any size. It does not include floating point ("real") types though.

You may use isSigned() to further check whether this data type allows negative numbers.

Note that this method also returns true on integer pointer types!

See also
isPointer()

Definition at line 242 of file Serialization.cpp.

Referenced by Serialization::Archive::setAutoValue().

◆ isMap()

bool Serialization::DataType::isMap ( ) const

Whether this is a C++ Map<> object type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is an associative sorted C++ Map<> container object type.

Note
: This framework handles Map<> types neither as primitive types, nor as class types. So isPrimitive() and isClass() both return false for maps.
See also
isPointer()

Definition at line 337 of file Serialization.cpp.

Referenced by isPrimitive().

◆ isPointer()

bool Serialization::DataType::isPointer ( ) const

Whether this is reflecting a C/C++ pointer type.

Returns @true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a C/C++ pointer type.

Definition at line 157 of file Serialization.cpp.

Referenced by asLongDescr(), and DataType().

◆ isPrimitive()

bool Serialization::DataType::isPrimitive ( ) const

Whether this is reflecting a fundamental C/C++ data type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a primitive, fundamental C/C++ data type. Those are fundamental data types which are already predefined by the C/C++ language, for example: char, int, float, double, bool, but also String objects and any pointer types like int*, double**, but including pointers to user defined types like:

struct Foo {
int a;
bool b;
};
Foo* pFoo;

So the DataType object of pFoo in the latter example would also return true for isPrimitive() here!

See also
isPointer()

Definition at line 210 of file Serialization.cpp.

References isArray(), isClass(), isMap(), and isSet().

◆ isReal()

bool Serialization::DataType::isReal ( ) const

Whether this is a floating point based C/C++ data type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a (fundamental, primitive) floating point based data type. So these are currently the C/C++ float and double types. It does not include integer types though.

Note that this method also returns true on float pointer and double pointer types!

See also
isPointer()

Definition at line 259 of file Serialization.cpp.

Referenced by isSigned(), and Serialization::Archive::setAutoValue().

◆ isSet()

bool Serialization::DataType::isSet ( ) const

Whether this is a C++ Set<> object type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a C++ Set<> unique container object type.

Note
: This framework handles Set<> types neither as primitive types, nor as class types. So isPrimitive() and isClass() both return false for sets.
See also
isPointer()

Definition at line 321 of file Serialization.cpp.

Referenced by isPrimitive().

◆ isSigned()

bool Serialization::DataType::isSigned ( ) const

Whether this is a signed integer C/C++ data type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a (fundamental, primitive) signed integer data type. This is the case for are all unsigned int C/C++ types of any size. For all floating point ("real") based types this method returns false though!

Note that this method also returns true on signed integer pointer types!

See also
isInteger();

Definition at line 354 of file Serialization.cpp.

References isReal().

Referenced by Serialization::Archive::setIntValue().

◆ isString()

bool Serialization::DataType::isString ( ) const

Whether this is a C++ String data type.

Returns true if the respective native C/C++ object, member or variable (this DataType instance is reflecting) is a C++ String object (a.k.a. std::string from the C++ STL).

Note that this framework handles String objects as if they were a fundamental, primitive C/C++ data type, so isPrimitive() returns true for strings.

Definition at line 224 of file Serialization.cpp.

Referenced by Serialization::Archive::setAutoValue().

◆ isValid()

bool Serialization::DataType::isValid ( ) const

Check if this is a valid DataType object.

Returns true if this DataType object is reflecting a valid data type. The default constructor creates DataType objects initialized to be "invalid" DataType objects by default. That way one can detect whether a DataType object was ever assigned to something meaningful.

Note that this class also implements the bool operator, both return the same boolean result.

Definition at line 148 of file Serialization.cpp.

Referenced by operator bool().

◆ newInstance()

Object Serialization::DataType::newInstance ( Archive archive) const
protected

Allocate and initialize a native instance of data type.

This is basically like calling the C++ new operator for the native data type, though by calling this reflection API instead. Thus memory for one instance of the data type is allocated on the heap and initialized by data types's default constructor.

Consequently this method can only be called for native data types that do have a default constructor. For data types that do not have a default constructor, calling this method will cause an assertion fault.

Returns
new Object reflecting the newly allocated native data instance

Definition at line 600 of file Serialization.cpp.

References internalID().

◆ operator!=()

bool Serialization::DataType::operator!= ( const DataType other) const

Comparison for inequalness.

Returns the inverse result of what DataType::operator==() would return. So refer to the latter for more details.

Definition at line 411 of file Serialization.cpp.

References operator==().

◆ operator<()

bool Serialization::DataType::operator< ( const DataType other) const

Smaller than comparison.

Returns true if this DataType object can be consider to be "smaller" than the other DataType object being compared with. This operator is actually quite arbitrarily implemented and may change at any time, and thus result for the same data types may change in future at any time.

This operator is basically implemented for allowing this DataType class to be used with various standard template library (STL) classes, which require sorting operators to be implemented.

Definition at line 426 of file Serialization.cpp.

Referenced by operator>().

◆ operator==()

bool Serialization::DataType::operator== ( const DataType other) const

Comparison for equalness.

Returns true if the two DataType objects being compared can be considered to be "equal" C/C++ data types. They are considered to be equal if their underlying C/C++ data types are exactly identical. For example comparing int and unsigned int data types are considere to be not equal, since they are differently signed. Furthermore short int and long int would also not be considered to be equal, since they do have a different memory size. Additionally pointer type characteristic is compared as well. So a double type and double* type are also considered to be not equal data types and hence this method would return false.

As an exception here, classes and structs with the same class/struct name but different sizes are also considered to be "equal". This relaxed requirement is necessary to retain backward compatibility to older versions of the same native C++ classes/structs.

Definition at line 377 of file Serialization.cpp.

References isClass().

Referenced by operator!=(), and operator>().

◆ operator>()

bool Serialization::DataType::operator> ( const DataType other) const

Greater than comparison.

Returns true if this DataType object can be consider to be "greater" than the other DataType object being compared with. This operator is actually quite arbitrarily implemented and may change at any time, and thus result for the same data types may change in future at any time.

This operator is basically implemented for allowing this DataType class to be used with various standard template library (STL) classes, which require sorting operators to be implemented.

Definition at line 449 of file Serialization.cpp.

References operator<(), and operator==().

◆ registerNativeDataType()

template<typename T >
void Serialization::DataType::registerNativeDataType
static

Manual registration of native C++ data types.

This method allows applications to explicitly register native C/C++ data types to this framework, for the purpose to allow creating new instances of those data types by this framework's reflection API at runtime.

@discussion Mostly it is not necessary to manually register native C/C++ data types, as this framework automatically collects required information about applications' data types at compile-time. There are rare cases though where an application needs to register some native data types explicitly to this Serialization framework by either calling DataType::registerNativeType() or by using class NativeDataTypeRegistry, before doing any (de)serialization.

For instance: if the application serializes only base class pointers and all of the sudden some of these pointers point to objects of derived classes AND this framework did not get into touch with those derived class(es) elsewhere, in this example the deriving classe(s) either might need to be registered manually, or some member variable of that derived type needs to be serialized somewhere for this framework to gather the required type information at compile time instead.

Example:

void appsInitCode() {
Serialization::DataType::registerNativeType<MyType>();
}
See also
NativeDataTypeRegistry for registration at global C++ declaration space

Definition at line 1950 of file Serialization.h.

References dataTypeOf(), and internalID().

Referenced by dataTypeOf().


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