Function qpid_proton_sys::pn_message_set_content_type

pub unsafe extern "C" fn pn_message_set_content_type(
    msg: *mut pn_message_t, 
    param_type: *const c_char
) -> i32

Set the content_type for a message. The supplied content_type pointer must either be NULL or reference a NUL terminated string. When the pointer is NULL, the content_type is set to NULL. When the pointer is non NULL, the contents are copied into the message.