Examples of macros: inside reify, only .splice, not .value can be called on Expr

ExprSplice.scala

import scala.reflect.makro.Context
import language.experimental.macros
def macroId[A](c: Context)(v: c.Expr[A]): c.Expr[A] = c.reify(v.splice)
def id2[A](v: A) = macro macroId[A]
id2(1)

ExprSpliceLog.scala

//Show that with Expr.splice works
$ ~/opt/scala-2.10.0-M5/bin/scala -Xlog-free-terms

Welcome to Scala version 2.10.0-M5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_33).
Type in expressions to have them evaluated.
Type :help for more information.

scala> import scala.reflect.makro.Context
import scala.reflect.makro.Context

scala> import language.experimental.macros
import language.experimental.macros

scala> def macroId[A](c: Context)(v: c.Expr[A]): c.Expr[A] = c.reify(v.splice)
macroId: [A](c: scala.reflect.makro.Context)(v: c.Expr[A])c.Expr[A]

scala> def id2[A](v: A) = macro macroId[A]
id2: [A](v: A)A

scala> id2(1)
res0: Int = 1

ExprValue.scala

import scala.reflect.makro.Context
import language.experimental.macros
def macroId[A](c: Context)(v: c.Expr[A]): c.Expr[A] = c.reify(v.value)
def id2[A](v: A) = macro macroId[A]
id2(1)

ExprValueLog.scala

//Show problem with Expr.value
$ ~/opt/scala-2.10.0-M5/bin/scala -Xlog-free-terms
Welcome to Scala version 2.10.0-M5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_33).
Type in expressions to have them evaluated.
Type :help for more information.

scala> import scala.reflect.makro.Context
import scala.reflect.makro.Context

scala> import language.experimental.macros
import language.experimental.macros

scala> def macroId[A](c: Context)(v: c.Expr[A]): c.Expr[A] = c.reify(v.value)
<console>:9: free term: Ident(newTermName("c")) defined by macroId in <console>:9:23
       def macroId[A](c: Context)(v: c.Expr[A]): c.Expr[A] = c.reify(v.value)
                                                                    ^
<console>:9: free term: Ident(newTermName("v")) defined by macroId in <console>:9:35
       def macroId[A](c: Context)(v: c.Expr[A]): c.Expr[A] = c.reify(v.value)
                                                                    ^
macroId: [A](c: scala.reflect.makro.Context)(v: c.Expr[A])c.Expr[A]

scala> def id2[A](v: A) = macro macroId[A]
id2: [A](v: A)A

scala> id2(1)
<console>:12: error: Macro expansion contains free term variable v defined by macroId in <console>:9:35. Have you forgotten to use splice when splicing this variable into a reifee? If you have troubles tracking free term variables, consider using -Xlog-free-terms
              id2(1)
                 ^