This document proposes a new mapping from IDL to C++11. The mapping aims to simplify the existing IDL to C++ mapping by taking advantage of new C++11 features to gain performance, reduce errors and code, and remove the need for conversions between IDL and C++ types. It outlines high-level concepts like mapping basic IDL types to C++11 counterparts. It also describes how interfaces, arguments, structs/unions would be mapped. A proof-of-concept implementation called IDL2C++11 is mentioned along with next steps to address comments and expand the mapping.

1. IDL to C++0x/C++11
Initial submission
OMG document mars/2011-09-04
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2. RFP asks for
The new mapping should be functionally equivalent to the existing
IDL to C++ mapping. While the syntax may change, an application
should be able to implement functionality identical to that which can
be achieved with the current IDL to C++ mapping.
Applications programmed using alternative language mappings
should inter operate transparently. An application utilizing this new
language mapping should have no awareness, other than
informational, of what language mapping a peer application is using.
The new language mapping should be designed to co-exist with
other technologies. Specifically, it should not interfere with the
namespaces used by other OMG specifications, or commonly used
packages.
Interoperability between the IDL to C++ and IDL to C++0x mapping in
the same compilation unit is not required.
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3. C++11
C++0x was unanimously approved August 12 th
2011
Is now formally available as ISO/IEC 14882:2011
Unofficially named C++11
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4. Goal of IDL to C++11
Simplified mapping for C++11
Make use of the new C++11 features to
– Gain performance
– Reduce coding errors
– Reduce amount of code
– No need to create conversion between STL/C++
types and IDL based types
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5. Concepts
Map basic types to their C++11 counterparts
IDL (w)string map to std::(w)string
IDL sequences map to std::vector
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6. Interface mapping
When defining interface Foo, than Foo is the
object reference
C++ traits are used to determine the type for
the proxy and skeleton base classes, not the
name and how they are implemented
– Foo::local_base_type
– Foo::servant_type
– Foo::servant_base_type
Foo as object reference has the semantics of
std::shared_ptr<>
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7. Nil object references
C++11 has a new type for a nil pointer: nullptr_t
Object references can be checked for nil by
comparing them with nullptr
Explicit bool conversion operators for usage in
for example if statements
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8. Argument passing
Argument passing is the same for any type
– in: const T&
– inout: T&
– out: T&
– return: T
C++ method interfaces will not change if for
example a typedef is changed from basic type
to complex type.
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9. Struct/union
Struct and union now both map to a C++ class
Providing constructor(s), copy and move
operators
Set of accessors for each member:
– void A (const T&);
– void A (T&&);
– const T& A (void) const;
– T& A (void);
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10. What next?
Address comments on initial submission
Add mapping for arrays/abstract/valuetype/any
Extend mapping with sequence traits, ostream
insertion operators, and more if needed
Check out IDL annotations when they are part of
the formal IDL specification. Mostly interesting for
user defined mapping of IDL types.
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11. Proof of concept
New language binding for TAO: IDL2C++11
Supports the initial submission and more
More details on http://osportal.remedy.nl and
http://www.orbzone.org
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12. Thanks for your attention
Johnny Willemsen
<jwillemsen@remedy.nl>
http://www.theaceorb.nl
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