NullPointer Cannot read the array length because "<local3>" is null

[siddhsql]

Hello,

I am trying to use this library to interface with some C++ code. My C++ header is like this:

struct Foo {
    std::string str;
    std::vector<char32_t> chars;    
};

std::vector<Foo> myfun(const std::string& str);

How can I map this to Java? I am trying:

public static class Foo extends Pointer {
        @Name("getStr")
        @StdString
        public native String str(); 
        @Name("getChars")
        @StdVector @Cast("char32_t*")   // https://github.com/bytedeco/javacpp/issues/159#issuecomment-272584503
        public native int[] chars(); 
    }

    @StdVector("Foo")
    public static native Foo[] myfun(        @StdString String s    );

but when I call myfun I get:

NullPointer Cannot read the array length because "<local3>" is null

The problem is when the function is returning the values. the null pointer is the return value Foo[].

[saudet]

Foo is already a Pointer, remove the []

[siddhsql]

my function is returning a std::vector<Foo>. could you explain more please? thanks.

…

On Wed, Jan 29, 2025 at 3:04 PM Samuel Audet ***@***.***> wrote: Foo is already a Pointer, remove the [] — Reply to this email directly, view it on GitHub <#795 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6NWEK2YQ6P275B3XXNADA32NFM6BAVCNFSM6AAAAABWDPS36CVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTEMBQGA4TQMA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[saudet]

So try @StdVector Foo instead

[siddhsql]

if the C++ function returns a std::vector<Foo> then doesn't the Java method has to return either an array or an ArrayList?

…

On Wed, Jan 29, 2025 at 5:18 PM Samuel Audet ***@***.***> wrote: So try @stdvector Foo instead — Reply to this email directly, view it on GitHub <#795 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6NWEKZJUBABFICTDTGW35L2NF4W5AVCNFSM6AAAAABWDPS36CVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTEMBQGE3TGNA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[saudet]

Are you getting an error when using @StdVector Foo?