operator = does not work with fstream

I am having a structure

struct myStruct {
    fstream fp;
    char *buffer;
    size_t size;
};

I am new to C++ and trying to write a code wherein one thread will read from a file into buffer and main thread will write the buffer to other file. The sample of the code is as follows:

int main() {
    pthread tid1;
    struct myStruct readArgs;
    fstream fileP, fileP2;
    fileP.open("/tmp/20MBFile", fstream::in);
    fileP2.open("/tmp/trial-file", fstream::out);
    char *buffer;
    readArgs.fp = fileP;
    readArgs.buffer = buffer;
    readArgs.size = 1048576;
    pthread_create(&tid1, NULL, Read, &readArgs);
    pthread_join(tid1, NULL);
    fileP2.write(buffer, 1048576);
    ......
}

The read function is as follows:

void *Read(struct myStruct *readArgs) {
    readArgs->fp.read(readArgs->buffer, readArgs->size);
    pthread_exit(NULL);
}

however, when I compile my code I get following errors:

error: use of deleted function 'std::basic_fstream& std::basic_fstream::operator=(const std::basic_fstream&)' readArgs.fp = fileP;

AND

error: invalid conversion from 'void* ()(myStruct)' to 'void* ()(void)' [-fpermissive] pthread_create(&tid1, NULL, Read, &readArgs); ^ In file included from /usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../include/c++/4.8.3/x86_64-redhat-linux/bits/gthr-default.h:35:0, from /usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../include/c++/4.8.3/x86_64-redhat-linux/bits/gthr.h:148, from /usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../include/c++/4.8.3/ext/atomicity.h:35, from /usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../include/c++/4.8.3/bits/ios_base.h:39, from /usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../include/c++/4.8.3/ios:42, from /usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../include/c++/4.8.3/ostream:38, from /usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../include/c++/4.8.3/iostream:39, from projects/sshsm/experiments/common/bufferpool.h:1, from projects/sshsm/experiments/common/bufferpool.cc:2: /usr/include/pthread.h:232:12: error: initializing argument 3 of 'int pthread_create(pthread_t*, const pthread_attr_t*, void* ()(void), void*)' [-fpermissive] extern int pthread_create (pthread_t *__restrict __newthread,

Am I missing anything here? Thanks in advance!