feat: fix cstr ffi again

wfassoc-cdylib/src/lib.rs

@@ -12,6 +12,9 @@ mod wrapper;
 /// Error occurs in this crate.
 #[derive(Debug, TeError)]
 enum Error {
+    /// Error when operating Schema.
+    #[error("{0}")]
+    Schema(#[from] wfassoc::highlevel::SchemaError),
     /// Error when parsing Schema into Program.
     #[error("{0}")]
     ParseProgram(#[from] wfassoc::highlevel::ParseProgramError),
@@ -19,10 +22,9 @@ enum Error {
     #[error("{0}")]
     Program(#[from] wfassoc::highlevel::ProgramError),
 
-    #[error("error occurs when parsing into C/C++ string")]
-    CastIntoCStr(#[from] std::ffi::NulError),
-    #[error("error occurs when parsing from C/C++ string")]
-    CastFromCStr(#[from] std::ffi::IntoStringError),
+    /// Error when manipulating with C-style string.
+    #[error("{0}")]
+    CStrFfi(#[from] cstr_ffi::Error),
 }
 
 /// Result type used in this crate.
@@ -37,12 +39,12 @@ type Result<T> = std::result::Result<T, Error>;
 
 #[unsafe(no_mangle)]
 pub extern "C" fn WFStartup() -> bool {
-    false
+    true
 }
 
 #[unsafe(no_mangle)]
 pub extern "C" fn WFShutdown() -> bool {
-    false
+    true
 }
 
 #[unsafe(no_mangle)]