misc. copies in core/syntax to please borrowck

Author: nikomatsakis

src/libcore/future.rs

@@ -108,7 +108,7 @@ fn get<A:copy>(future: future<A>) -> A {
 fn with<A,B>(future: future<A>, blk: fn(A) -> B) -> B {
     #[doc = "Work with the value without copying it"];
 
-    let v = alt future.v {
+    let v = alt copy future.v {
       either::left(v) { v }
       either::right(f) {
         let v = @f();

src/libcore/io.rs

@@ -613,7 +613,7 @@ impl of writer for mem_buffer {
         // FIXME #2004--use memcpy here?
         let mut pos = self.pos, vpos = 0u;
         while vpos < vlen && pos < buf_len {
-            self.buf.set_elt(pos, v[vpos]);
+            self.buf.set_elt(pos, copy v[vpos]);
             pos += 1u;
             vpos += 1u;
         }

src/libsyntax/ext/qquote.rs

@@ -212,7 +212,7 @@ fn finish<T: qq_helper>
             state = skip(str::char_len(repl));
             str2 += repl;
         }
-        alt state {
+        alt copy state {
           active {str::push_char(str2, ch);}
           skip(1u) {state = blank;}
           skip(sk) {state = skip (sk-1u);}

src/libsyntax/parse/token.rs

@@ -184,16 +184,16 @@ fn is_lit(t: token::token) -> bool {
         }
 }
 
-fn is_ident(t: token::token) -> bool {
+pure fn is_ident(t: token::token) -> bool {
     alt t { token::IDENT(_, _) { ret true; } _ { } }
     ret false;
 }
 
-fn is_plain_ident(t: token::token) -> bool {
+pure fn is_plain_ident(t: token::token) -> bool {
     ret alt t { token::IDENT(_, false) { true } _ { false } };
 }
 
-fn is_bar(t: token::token) -> bool {
+pure fn is_bar(t: token::token) -> bool {
     alt t { token::BINOP(token::OR) | token::OROR { true } _ { false } }
 }