eliminate method ambiguities

Author: stevengj

base/c.jl

@@ -129,24 +129,22 @@ Convert string data between Unicode encodings.   `src` is either a
 `String` or a `Vector{UIntXX}` of UTF-XX code units, where
 `XX` is 8, 16, or 32. `T` indicates the encoding of the return value:
 `String` to return a (UTF-8 encoded) `String` or `UIntXX`
-to return a `Vector{UIntXX}` of UTF-`XX` data.
+to return a `Vector{UIntXX}` of UTF-`XX` data.   Only conversion
+to or from UTF-8 is currently supported.
 """
 function transcode end
 
-transcode{T<:Union{UInt8,UInt16}}(::Type{T}, src::Vector{T}) = src
-transcode(T, src::String) = transcode(T, src.data)
-transcode(::Type{String}, src) = String(transcode(UInt8, src))
-
-transcode(::Type{Int32}, src::Vector{UInt32}) = reinterpret(Int32, src)
+transcode{T<:Union{UInt8,UInt16,UInt32,Int32}}(::Type{T}, src::Vector{T}) = src
 transcode{T<:Union{Int32,UInt32}}(::Type{T}, src::String) = T[T(c) for c in src]
-transcode{T<:Union{Int32,UInt32}}(::Type{T}, src) = transcode(T, transcode(String, src))
-transcode{S<:Union{Int32,UInt32}}(T, src::Vector{S}) = transcode(T, transcode(String, src))
-function transcode{S<:Union{Int32,UInt32}}(::Type{String}, src::Vector{S})
+transcode{T<:Union{Int32,UInt32}}(::Type{T}, src::Vector{UInt8}) = transcode(T, String(src))
+function transcode{S<:Union{Int32,UInt32}}(::Type{UInt8}, src::Vector{S})
     buf = IOBuffer()
     for c in src; print(buf, Char(c)); end
-    takebuf_string(buf)
+    takebuf_array(buf)
 end
-transcode(::Type{UInt16}, src::Vector) = transcode(UInt16, transcode(UInt8, src))
+transcode(::Type{String}, src::String) = src
+transcode(T, src::String) = transcode(T, src.data)
+transcode(::Type{String}, src) = String(transcode(UInt8, src))
 
 function transcode(::Type{UInt16}, src::Vector{UInt8})
     dst = UInt16[]

doc/stdlib/strings.rst

@@ -60,7 +60,7 @@
 
    .. Docstring generated from Julia source
 
-   Convert string data between Unicode encodings.   ``src`` is either a ``String`` or a ``Vector{UIntXX}`` of UTF-XX code units, where ``XX`` is 8, 16, or 32. ``T`` indicates the encoding of the return value: ``String`` to return a (UTF-8 encoded) ``String`` or ``UIntXX`` to return a ``Vector{UIntXX}`` of UTF-``XX`` data.
+   Convert string data between Unicode encodings.   ``src`` is either a ``String`` or a ``Vector{UIntXX}`` of UTF-XX code units, where ``XX`` is 8, 16, or 32. ``T`` indicates the encoding of the return value: ``String`` to return a (UTF-8 encoded) ``String`` or ``UIntXX`` to return a ``Vector{UIntXX}`` of UTF-``XX`` data.   Only conversion to or from UTF-8 is currently supported.
 
 .. function:: unsafe_string(p::Ptr{UInt8}, [length::Integer])
 
@@ -506,3 +506,4 @@
    .. Docstring generated from Julia source
 
    Create a string from the address of a NUL-terminated UTF-32 string. A copy is made; the pointer can be safely freed. If ``length`` is specified, the string does not have to be NUL-terminated.
+