array of structs

[mikazo]

I have the following code:

struct vertex2 {
	FLOAT x, y, z, rhw;
	DWORD color;
	FLOAT u, v;
};

struct vertex2 localBuffer[264];
localBuffer[0].x = 512.0f;

But I get the following compiler error:

1>------ Rebuild All started: Project: Erg, Configuration: Debug Win32 ------
1>Deleting intermediate and output files for project 'Erg', configuration 'Debug|Win32'
1>Compiling...
1>main.cpp
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(5) : error C2466: cannot allocate an array of constant size 0
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(5) : error C2143: syntax error : missing ';' before '.'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(5) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(5) : error C2371: 'localBuffer' : redefinition; different basic types
1>        c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(2) : see declaration of 'localBuffer'
1>Build log was saved at "file://c:\Users\Mike\Documents\Visual Studio 2008\Projects\Erg\Erg\Debug\BuildLog.htm"
1>Erg - 4 error(s), 0 warning(s)
========== Rebuild All: 0 succeeded, 1 failed, 0 skipped ==========

As far as I know it should work how it is.. can anyone please explain to me? Thanks.

-Mike

[zerver]

You cannot make assignments on the top level, only declarations.

However, it is possible to work around this limitation as follows:

float mydummyvariable1 = localBuffer[0].x = 512.0f;
float mydummyvariable2 = localBuffer[0].y = 1024.0f;
float mydummyvariable3 = localBuffer[0].z = 2048.0f;

[hoxsiew]

For C++, lose the "struct" part of your array declaration:

struct vertex2 {
	FLOAT x, y, z, rhw;
	DWORD color;
	FLOAT u, v;
};

vertex2 localBuffer[264];
localBuffer[0].x = 512.0f;

For C, tag your declaration then lose the "struct" as so:

struct tag_vertex2 {
	FLOAT x, y, z, rhw;
	DWORD color;
	FLOAT u, v;
}vertex2;

vertex2 localBuffer[264];
localBuffer[0].x = 512.0f;

(not tested)

[zerver]

With plain C you can also do:

typedef struct vertex2 vertex2;

[mikazo]

Thank you for the workaround, but I guess I should have mentioned that I'd prefer to execute the code as follows:

for (int i = 0; i < 100; i++)
      localBuffer[i].x = 10.0f;

The problem with that is that I can't really declare new dummy floats inside the loop. It seems strange to me that Visual C++ would disallow such a thing.

[hoxsiew]

What do you mean? That should work fine.

[mikazo]

Ok, now this is just weird.

This code

struct vertex2 localBuffer[264];
for (int i = 4; i < 264; i++) {
		localBuffer[i].x = 0.0f;

produces this error

1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2059: syntax error : 'for'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ')' before ';'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ';' before '<'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ';' before '++'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2086: 'int i' : redefinition
1>        c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : see declaration of 'i'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2059: syntax error : ')'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ';' before '{'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2447: '{' : missing function header (old-style formal list?)

Syntax error 'for'? There's no such thing as a for loop anymore?

[Lindley]

Try dropping the word "struct" from that as was suggested above.

[mikazo]

I've tried it with all of the following and still get errors:

struct vertex2 localBuffer[264];

vertex2 localBuffer[264];

struct vertex2 {
...
} Vertex2;
Vertex2 localBuffer[264];

[Lindley]

Try this one.

typedef struct vertex2 {
...
} Vertex2;
Vertex2 localBuffer[264];

[zerver]

You cannot write code on the top level. Your program needs a main function.

int main(int argc, char *argv[]) {
  for (int i = 0; i < 100; i++)
    localBuffer[i].x = 10.0f;
}

[Khiem]

Yes, but the OP programs in win32 application not console
Why doesn't OP use vector class ?

std::vector<vertex2>localBuffer;
struct or class is fine, no problem really

[Today I suddenly am in a better mood! Thanks for reading and sharing!]

Regards

Stupid ~V

[hoxsiew]

Ok, now this is just weird.

This code

struct vertex2 localBuffer[264];
for (int i = 4; i < 264; i++) {
		localBuffer[i].x = 0.0f;

produces this error

1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2059: syntax error : 'for'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ')' before ';'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ';' before '<'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ';' before '++'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2086: 'int i' : redefinition
1>        c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : see declaration of 'i'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2059: syntax error : ')'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2143: syntax error : missing ';' before '{'
1>c:\users\mike\documents\visual studio 2008\projects\erg\erg\localbuffer.h(38) : error C2447: '{' : missing function header (old-style formal list?)

Syntax error 'for'? There's no such thing as a for loop anymore?

Are you implementing this in your header file?

[Martin O]

mikazo, just post a SSCCE

[mikazo]

Ok I feel silly now. I've been initializing my buffer arrays in header files because they can get large and tedious, but when I went to initialize my localBuffer after it was declared, I totally forgot that you can't just execute code outside of main().

Thank you for spending time to help fix my stupid mistake.