diff --git a/src/libcore/num/int-template.rs b/src/libcore/num/int-template.rs
index 7f3a15621ac..27e3b0d04ea 100644
--- a/src/libcore/num/int-template.rs
+++ b/src/libcore/num/int-template.rs
@@ -17,7 +17,9 @@
 use char;
 use cmp::{Eq, Ord};
 use cmp;
+use to_str::ToStr;
 use from_str::FromStr;
+use num::{ToStrRadix, FromStrRadix};
 use num;
 use num::Num::from_int;
 use prelude::*;
@@ -212,70 +214,87 @@ impl T: num::Round {
     pure fn fract(&self) -> T { 0 }
 }
 
-/**
- * Parse a buffer of bytes
- *
- * # Arguments
- *
- * * buf - A byte buffer
- * * radix - The base of the number
- */
-pub pure fn parse_bytes(buf: &[u8], radix: uint) -> Option<T> {
-    if vec::len(buf) == 0u { return None; }
-    let mut i = vec::len(buf) - 1u;
-    let mut start = 0u;
-    let mut power = 1 as T;
+// String conversion functions and impl str -> num
 
-    if buf[0] == ('-' as u8) {
-        power = -1 as T;
-        start = 1u;
-    }
-    let mut n = 0 as T;
-    loop {
-        match char::to_digit(buf[i] as char, radix) {
-          Some(d) => n += (d as T) * power,
-          None => return None
-        }
-        power *= radix as T;
-        if i <= start { return Some(n); }
-        i -= 1u;
-    };
+/// Parse a string as a number in base 10.
+#[inline(always)]
+pub pure fn from_str(s: &str) -> Option<T> {
+    num::from_str_common(s, 10u, true, false, false,
+                         num::ExpNone, false)
 }
 
-/// Parse a string to an int
+/// Parse a string as a number in the given base.
 #[inline(always)]
-pub pure fn from_str(s: &str) -> Option<T>
-{
-    parse_bytes(str::to_bytes(s), 10u)
+pub pure fn from_str_radix(s: &str, radix: uint) -> Option<T> {
+    num::from_str_common(s, radix, true, false, false,
+                         num::ExpNone, false)
+}
+
+/// Parse a byte slice as a number in the given base.
+#[inline(always)]
+pub pure fn parse_bytes(buf: &[u8], radix: uint) -> Option<T> {
+    num::from_str_bytes_common(buf, radix, true, false, false,
+                               num::ExpNone, false)
 }
 
 impl T : FromStr {
     #[inline(always)]
-    static pure fn from_str(s: &str) -> Option<T> { from_str(s) }
-}
-
-/// Convert to a string in a given base
-#[inline(always)]
-pub pure fn to_str(n: T, radix: uint) -> ~str {
-    do to_str_bytes(n, radix) |slice| {
-        do vec::as_imm_buf(slice) |p, len| {
-            unsafe { str::raw::from_buf_len(p, len) }
-        }
+    static pure fn from_str(s: &str) -> Option<T> {
+        from_str(s)
     }
 }
 
+impl T : FromStrRadix {
+    #[inline(always)]
+    static pure fn from_str_radix(&self, s: &str, radix: uint) -> Option<T> {
+        from_str_radix(s, radix)
+    }
+}
+
+// String conversion functions and impl num -> str
+
+/// Convert to a string as a byte slice in a given base.
 #[inline(always)]
 pub pure fn to_str_bytes<U>(n: T, radix: uint, f: fn(v: &[u8]) -> U) -> U {
-    if n < 0 as T {
-        uint::to_str_bytes(true, -n as uint, radix, f)
-    } else {
-        uint::to_str_bytes(false, n as uint, radix, f)
+    let (buf, _) = num::to_str_bytes_common(&n, radix, false, false,
+                                            num::SignNeg, num::DigAll);
+    f(buf)
+}
+
+/// Convert to a string in base 10.
+#[inline(always)]
+pub pure fn to_str(num: T) -> ~str {
+    let (buf, _) = num::to_str_common(&num, 10u, false, false,
+                                      num::SignNeg, num::DigAll);
+    buf
+}
+
+/// Convert to a string in a given base.
+#[inline(always)]
+pub pure fn to_str_radix(num: T, radix: uint) -> ~str {
+    let (buf, _) = num::to_str_common(&num, radix, false, false,
+                                      num::SignNeg, num::DigAll);
+    buf
+}
+
+/// Convert to a string.
+/// *Deprecated*, use to_str() instead.
+#[inline(always)]
+pub pure fn str(i: T) -> ~str { to_str(i) }
+
+impl T : ToStr {
+    #[inline(always)]
+    pure fn to_str() -> ~str {
+        to_str(self)
     }
 }
 
-/// Convert to a string
-#[inline(always)]
-pub pure fn str(i: T) -> ~str { return to_str(i, 10u); }
+impl T : ToStrRadix {
+    #[inline(always)]
+    pure fn to_str_radix(&self, radix: uint) -> ~str {
+        to_str_radix(*self, radix)
+    }
+}
 
 #[test]
 fn test_from_str() {
@@ -322,11 +341,66 @@ fn test_parse_bytes() {
 
 #[test]
 fn test_to_str() {
-    assert (to_str(0 as T, 10u) == ~"0");
-    assert (to_str(1 as T, 10u) == ~"1");
-    assert (to_str(-1 as T, 10u) == ~"-1");
-    assert (to_str(127 as T, 16u) == ~"7f");
-    assert (to_str(100 as T, 10u) == ~"100");
+    assert (to_str_radix(0 as T, 10u) == ~"0");
+    assert (to_str_radix(1 as T, 10u) == ~"1");
+    assert (to_str_radix(-1 as T, 10u) == ~"-1");
+    assert (to_str_radix(127 as T, 16u) == ~"7f");
+    assert (to_str_radix(100 as T, 10u) == ~"100");
+
+}
+
+#[test]
+fn test_int_to_str_overflow() {
+    let mut i8_val: i8 = 127_i8;
+    assert (i8::to_str(i8_val) == ~"127");
+    
+    i8_val += 1 as i8;
+    assert (i8::to_str(i8_val) == ~"-128");
+
+    let mut i16_val: i16 = 32_767_i16;
+    assert (i16::to_str(i16_val) == ~"32767");
+    
+    i16_val += 1 as i16;
+    assert (i16::to_str(i16_val) == ~"-32768");
+
+    let mut i32_val: i32 = 2_147_483_647_i32;
+    assert (i32::to_str(i32_val) == ~"2147483647");
+    
+    i32_val += 1 as i32;
+    assert (i32::to_str(i32_val) == ~"-2147483648");
+
+    let mut i64_val: i64 = 9_223_372_036_854_775_807_i64;
+    assert (i64::to_str(i64_val) == ~"9223372036854775807");
+    
+    i64_val += 1 as i64;
+    assert (i64::to_str(i64_val) == ~"-9223372036854775808");
+}
+
+#[test]
+fn test_int_from_str_overflow() {
+    let mut i8_val: i8 = 127_i8;
+    assert (i8::from_str(~"127") == Some(i8_val));
+    
+    i8_val += 1 as i8;
+    assert (i8::from_str(~"-128") == Some(i8_val));
+
+    let mut i16_val: i16 = 32_767_i16;
+    assert (i16::from_str(~"32767") == Some(i16_val));
+    
+    i16_val += 1 as i16;
+    assert (i16::from_str(~"-32768") == Some(i16_val));
+
+    let mut i32_val: i32 = 2_147_483_647_i32;
+    assert (i32::from_str(~"2147483647") == Some(i32_val));
+    
+    i32_val += 1 as i32;
+    assert (i32::from_str(~"-2147483648") == Some(i32_val));
+
+    let mut i64_val: i64 = 9_223_372_036_854_775_807_i64;
+    assert (i64::from_str(~"9223372036854775807") == Some(i64_val));
+    
+    i64_val += 1 as i64;
+    assert (i64::from_str(~"-9223372036854775808") == Some(i64_val));
 }
 
 #[test]
diff --git a/src/libcore/to_str.rs b/src/libcore/to_str.rs
index b1fb1fdd483..054512811be 100644
--- a/src/libcore/to_str.rs
+++ b/src/libcore/to_str.rs
@@ -24,26 +24,6 @@
 
 pub trait ToStr { pub pure fn to_str() -> ~str; }
 
-impl int: ToStr {
-    #[inline(always)]
-    pure fn to_str() -> ~str { ::int::str(self) }
-}
-impl i8: ToStr {
-    #[inline(always)]
-    pure fn to_str() -> ~str { ::i8::str(self) }
-}
-impl i16: ToStr {
-    #[inline(always)]
-    pure fn to_str() -> ~str { ::i16::str(self) }
-}
-impl i32: ToStr {
-    #[inline(always)]
-    pure fn to_str() -> ~str { ::i32::str(self) }
-}
-impl i64: ToStr {
-    #[inline(always)]
-    pure fn to_str() -> ~str { ::i64::str(self) }
-}
 impl uint: ToStr {
     #[inline(always)]
     pure fn to_str() -> ~str { ::uint::str(self) }
diff --git a/src/librustc/driver/driver.rs b/src/librustc/driver/driver.rs
index 7f7c0114988..3dd49f661ee 100644
--- a/src/librustc/driver/driver.rs
+++ b/src/librustc/driver/driver.rs
@@ -382,21 +382,21 @@ fn ann_identified_post(node: pprust::ann_node) {
         match node {
           pprust::node_item(s, item) => {
             pp::space(s.s);
-            pprust::synth_comment(s, int::to_str(item.id, 10u));
+            pprust::synth_comment(s, int::to_str(item.id));
           }
           pprust::node_block(s, ref blk) => {
             pp::space(s.s);
             pprust::synth_comment(
-                s, ~"block " + int::to_str((*blk).node.id, 10u));
+                s, ~"block " + int::to_str((*blk).node.id));
           }
           pprust::node_expr(s, expr) => {
             pp::space(s.s);
-            pprust::synth_comment(s, int::to_str(expr.id, 10u));
+            pprust::synth_comment(s, int::to_str(expr.id));
             pprust::pclose(s);
           }
           pprust::node_pat(s, pat) => {
             pp::space(s.s);
-            pprust::synth_comment(s, ~"pat " + int::to_str(pat.id, 10u));
+            pprust::synth_comment(s, ~"pat " + int::to_str(pat.id));
           }
         }
     }
diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index 33879237ffb..b8a1b942453 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -245,7 +245,7 @@ fn encode_discriminant(ecx: @encode_ctxt, ebml_w: writer::Encoder,
 fn encode_disr_val(_ecx: @encode_ctxt, ebml_w: writer::Encoder,
                    disr_val: int) {
     ebml_w.start_tag(tag_disr_val);
-    ebml_w.writer.write(str::to_bytes(int::to_str(disr_val,10u)));
+    ebml_w.writer.write(str::to_bytes(int::to_str(disr_val)));
     ebml_w.end_tag();
 }
 
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index f394c98ab6f..5a8fe94a439 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -679,7 +679,7 @@ fn iter_variant(cx: block, a_tup: ValueRef,
             let variant_cx =
                 sub_block(cx,
                                    ~"enum-iter-variant-" +
-                                       int::to_str(variant.disr_val, 10u));
+                                       int::to_str(variant.disr_val));
             AddCase(llswitch, C_int(ccx, variant.disr_val), variant_cx.llbb);
             let variant_cx =
                 iter_variant(variant_cx, llunion_a_ptr, *variant,
diff --git a/src/test/run-pass/reflect-visit-data.rs b/src/test/run-pass/reflect-visit-data.rs
index 3ea8ef23ea9..96bddf7099b 100644
--- a/src/test/run-pass/reflect-visit-data.rs
+++ b/src/test/run-pass/reflect-visit-data.rs
@@ -517,7 +517,7 @@ fn visit_bool(&self) -> bool {
     }
     fn visit_int(&self) -> bool {
       do self.get::<int>() |i| {
-            self.vals += ~[int::to_str(i, 10u)];
+            self.vals += ~[int::to_str(i)];
       };
       true
     }