mystified by compiler error

[divideby0]

I've got a project with five C source files, one CPP source file and a single header such as

#ifndef __MYHEADER__
 
// basic includes
// several defines
// a few globals
 
typedef struct
{
   // data
} foo_1;
 
#if __cplusplus
 extern "C" {
#endif
 
// number of function prototypes for cpp source file
 
#if __cplusplus
}
#endif
 
// function prototypes for c source files
 
#endif
 

all source files include this header

Everything above compiles without errors or warnings. When I modify the above header to include another structure and a function prototype, I get compiler errors that strangely can be corrected using the "struct" keyword in the prototype and definition.

// modified header
 
typedef struct
{
   // data
} foo_1;
 
typedef struct
{
    // data
} foo_2;
 
// new prototype
 
void foo_bar(foo_2 *);
 

In C source file

void foo_bar(foo_2 *bar)
{
   // function def
}
 

error C2143: syntax error : missing ')' before '*'
error C2143: syntax error : missing '{' before '*'
error C2059: syntax error : ')'
error C2059: syntax error : ';'

If I change the function to below, the errors mysteriously go away.

void foo_bar(struct foo_2 *);
void foo_bar(struct foo_2 *bar)
{
  //
}

If I typedef the struct, why is seemingly losing the type? I've never had an issue like this before; what is the cause of this?

TIA

[weaknessforcats]

In C you must code struct foo_2*.

In C++ you can just code foo_2*.

C++ is not C. Doesn't work like C and some C won't compile as C++.

BTW this code:

#ifndef __MYHEADER__

should have a #define __MYHEADER__ as the next line.

[divideby0]

thanks wfc.

I figured out what the problem was; the IDE set the path of the C source file to an older project folder, which didn't have the structures defined in the samely named header file of the older project. I updated the path, and it worked as expected.

Thank you for taking the time to look; I do appreciate it.