C++/CLI DateTime method argument

[soren.enemaerke@gmail.com]

Hi everybody.

I'm writing a .NET wrapper class for a native C++ library and decided
to do it in C++/CLI. One of the problems I ran in to is the following.

In C++ I have the following

public ref class MyClass
{
....
bool DoIt(DateTime^% date);
bool DoIt2([OutAttribute] DateTime^% date)
}

which I think should translate into a method calls with c# syntax:

bool DoIt(ref DateTime date);
bool DoIt2(out DateTime date);

So I was a bit puzzled when the following showed up:

bool DoIt(ref ValueType date);

Where is my type safety? What am I doing wrong? Am I trying to do
something (returning value types from c++/cli via ref and out) that is
just not possible?

bool DoIt(ref ValueType date);

[Ben Voigt [C++ MVP]]

Re: C++/CLI DateTime method argument


<soren.enemaerk e@gmail.comwrot e in message
news:1190753360 .562742.319860@ 22g2000hsm.goog legroups.com...

Hi everybody.
>
I'm writing a .NET wrapper class for a native C++ library and decided
to do it in C++/CLI. One of the problems I ran in to is the following.
>
In C++ I have the following
>
public ref class MyClass
{
...
bool DoIt(DateTime^% date);
bool DoIt2([OutAttribute] DateTime^% date)
}
>
which I think should translate into a method calls with c# syntax:
>
bool DoIt(ref DateTime date);
bool DoIt2(out DateTime date);
>
So I was a bit puzzled when the following showed up:
>
bool DoIt(ref ValueType date);
>
Where is my type safety? What am I doing wrong? Am I trying to do
something (returning value types from c++/cli via ref and out) that is
just not possible?

You're using tracking handles (^) with a value type, which is not needed or
desired.

Just "bool DoIt(DateTime% date);" will work properly.

>
bool DoIt(ref ValueType date);
>

[soren.enemaerke@gmail.com]

Re: C++/CLI DateTime method argument

On 25 Sep., 23:24, "Ben Voigt [C++ MVP]" <r...@nospam.no spamwrote:

<soren.enemae.. .@gmail.comwrot e in message
>
news:1190753360 .562742.319860@ 22g2000hsm.goog legroups.com...
>
>
>
>
>

Hi everybody.

>

I'm writing a .NET wrapper class for a native C++ library and decided
to do it in C++/CLI. One of the problems I ran in to is the following.

>

In C++ I have the following

>

public ref class MyClass
{
...
bool DoIt(DateTime^% date);
bool DoIt2([OutAttribute] DateTime^% date)
}

>

which I think should translate into a method calls with c# syntax:

>

bool DoIt(ref DateTime date);
bool DoIt2(out DateTime date);

>

So I was a bit puzzled when the following showed up:

>

bool DoIt(ref ValueType date);

>

Where is my type safety? What am I doing wrong? Am I trying to do
something (returning value types from c++/cli via ref and out) that is
just not possible?

>
You're using tracking handles (^) with a value type, which is not needed or
desired.
>
Just "bool DoIt(DateTime% date);" will work properly.
>
>
>
>
>

bool DoIt(ref ValueType date);- Skjul tekst i anførselstegn -

>
- Vis tekst i anførselstegn -- Skjul tekst i anførselstegn -
>
- Vis tekst i anførselstegn -

Thanks Ben, worked like a charm.

[Sheng Jiang[MVP]]

Re: C++/CLI DateTime method argument

DateTime is a value type, however the track handle ^ makes the parameter to
be boxed. C# does not understand the type of a boxed value type, but C++/CLI
does. So you have ref ValueType in C#, and DateTime^ in C++/CLI.
--
Sheng Jiang
Microsoft MVP in VC++
<soren.enemaerk e@gmail.comwrot e in message
news:1190753360 .562742.319860@ 22g2000hsm.goog legroups.com...

Hi everybody.
>
I'm writing a .NET wrapper class for a native C++ library and decided
to do it in C++/CLI. One of the problems I ran in to is the following.
>
In C++ I have the following
>
public ref class MyClass
{
...
bool DoIt(DateTime^% date);
bool DoIt2([OutAttribute] DateTime^% date)
}
>
which I think should translate into a method calls with c# syntax:
>
bool DoIt(ref DateTime date);
bool DoIt2(out DateTime date);
>
So I was a bit puzzled when the following showed up:
>
bool DoIt(ref ValueType date);
>
Where is my type safety? What am I doing wrong? Am I trying to do
something (returning value types from c++/cli via ref and out) that is
just not possible?
>
bool DoIt(ref ValueType date);
>