diff --git a/examples/repl/main.rs b/examples/repl/main.rs
index 465a05c3d..41fc28126 100644
--- a/examples/repl/main.rs
+++ b/examples/repl/main.rs
@@ -320,10 +320,8 @@ unsafe fn main_0(argc: libc::c_int, argv: *mut *mut libc::c_char) -> libc::c_int
             || strcmp(cmd, b"getbadqr\x00" as *const u8 as *const libc::c_char) == 0i32
         {
             handles = Some(start_threads(ctx.clone()));
-            let qrstr: *mut libc::c_char = dc_get_securejoin_qr(
-                &ctx.read().unwrap(),
-                (if !arg1.is_null() { atoi(arg1) } else { 0i32 }) as uint32_t,
-            );
+            let qrstr: *mut libc::c_char =
+                dc_get_securejoin_qr(&ctx.read().unwrap(), dc_atoi_null_is_0(arg1) as u32);
             if !qrstr.is_null() && 0 != *qrstr.offset(0isize) as libc::c_int {
                 if strcmp(cmd, b"getbadqr\x00" as *const u8 as *const libc::c_char) == 0i32
                     && strlen(qrstr) > 40
diff --git a/src/dc_array.rs b/src/dc_array.rs
index d50a54813..95c7bf0ad 100644
--- a/src/dc_array.rs
+++ b/src/dc_array.rs
@@ -62,9 +62,7 @@ pub unsafe fn dc_array_add_uint(mut array: *mut dc_array_t, item: uintptr_t) {
             (*array).array as *mut libc::c_void,
             (newsize).wrapping_mul(::std::mem::size_of::<uintptr_t>()),
         ) as *mut uintptr_t;
-        if (*array).array.is_null() {
-            exit(49i32);
-        }
+        assert!(!(*array).array.is_null());
         (*array).allocated = newsize as size_t
     }
     *(*array).array.offset((*array).count as isize) = item;
@@ -266,9 +264,8 @@ pub unsafe fn dc_array_new(initsize: size_t) -> *mut dc_array_t {
 pub unsafe fn dc_array_new_typed(type_0: libc::c_int, initsize: size_t) -> *mut dc_array_t {
     let mut array: *mut dc_array_t;
     array = calloc(1, ::std::mem::size_of::<dc_array_t>()) as *mut dc_array_t;
-    if array.is_null() {
-        exit(47i32);
-    }
+    assert!(!array.is_null());
+
     (*array).magic = 0xa11aai32 as uint32_t;
     (*array).count = 0i32 as size_t;
     (*array).allocated = if initsize < 1 { 1 } else { initsize };
diff --git a/src/dc_chatlist.rs b/src/dc_chatlist.rs
index 0332bb9e7..420e00b54 100644
--- a/src/dc_chatlist.rs
+++ b/src/dc_chatlist.rs
@@ -83,15 +83,12 @@ pub unsafe fn dc_get_chatlist<'a>(
 pub unsafe fn dc_chatlist_new(context: &Context) -> *mut dc_chatlist_t {
     let mut chatlist: *mut dc_chatlist_t;
     chatlist = calloc(1, ::std::mem::size_of::<dc_chatlist_t>()) as *mut dc_chatlist_t;
-    if chatlist.is_null() {
-        exit(20i32);
-    }
+    assert!(!chatlist.is_null());
+
     (*chatlist).magic = 0xc4a71157u32;
     (*chatlist).context = context;
     (*chatlist).chatNlastmsg_ids = dc_array_new(128i32 as size_t);
-    if (*chatlist).chatNlastmsg_ids.is_null() {
-        exit(32i32);
-    }
+    assert!(!(*chatlist).chatNlastmsg_ids.is_null());
     chatlist
 }
 
diff --git a/src/dc_configure.rs b/src/dc_configure.rs
index c59c5e2bd..374e39a09 100644
--- a/src/dc_configure.rs
+++ b/src/dc_configure.rs
@@ -1406,7 +1406,7 @@ unsafe fn moz_autoconfigure_text_cb(
                 (*(*moz_ac).out).mail_server = val;
                 val = 0 as *mut libc::c_char
             }
-            11 => (*(*moz_ac).out).mail_port = atoi(val),
+            11 => (*(*moz_ac).out).mail_port = dc_atoi_null_is_0(val),
             12 => {
                 free((*(*moz_ac).out).mail_user as *mut libc::c_void);
                 (*(*moz_ac).out).mail_user = val;
@@ -1432,7 +1432,7 @@ unsafe fn moz_autoconfigure_text_cb(
                 (*(*moz_ac).out).send_server = val;
                 val = 0 as *mut libc::c_char
             }
-            11 => (*(*moz_ac).out).send_port = atoi(val),
+            11 => (*(*moz_ac).out).send_port = to_str(val).parse().unwrap_or_default(),
             12 => {
                 free((*(*moz_ac).out).send_user as *mut libc::c_void);
                 (*(*moz_ac).out).send_user = val;
diff --git a/src/dc_contact.rs b/src/dc_contact.rs
index b4a69e528..ed7355abf 100644
--- a/src/dc_contact.rs
+++ b/src/dc_contact.rs
@@ -240,9 +240,8 @@ pub unsafe fn dc_block_contact(context: &Context, contact_id: uint32_t, new_bloc
 pub unsafe fn dc_contact_new<'a>(context: &'a Context) -> *mut dc_contact_t<'a> {
     let mut contact: *mut dc_contact_t;
     contact = calloc(1, ::std::mem::size_of::<dc_contact_t>()) as *mut dc_contact_t;
-    if contact.is_null() {
-        exit(19i32);
-    }
+    assert!(!contact.is_null());
+
     (*contact).magic = 0xc047ac7i32 as uint32_t;
     (*contact).context = context;
 
diff --git a/src/dc_loginparam.rs b/src/dc_loginparam.rs
index 3475f2499..3f18a23ec 100644
--- a/src/dc_loginparam.rs
+++ b/src/dc_loginparam.rs
@@ -23,9 +23,7 @@ pub struct dc_loginparam_t {
 pub unsafe fn dc_loginparam_new() -> *mut dc_loginparam_t {
     let loginparam: *mut dc_loginparam_t;
     loginparam = calloc(1, ::std::mem::size_of::<dc_loginparam_t>()) as *mut dc_loginparam_t;
-    if loginparam.is_null() {
-        exit(22i32);
-    }
+    assert!(!loginparam.is_null());
 
     loginparam
 }
diff --git a/src/dc_lot.rs b/src/dc_lot.rs
index c913258e1..2903a385c 100644
--- a/src/dc_lot.rs
+++ b/src/dc_lot.rs
@@ -36,9 +36,8 @@ pub struct dc_lot_t {
 pub unsafe fn dc_lot_new() -> *mut dc_lot_t {
     let mut lot: *mut dc_lot_t;
     lot = calloc(1, ::std::mem::size_of::<dc_lot_t>()) as *mut dc_lot_t;
-    if lot.is_null() {
-        exit(27i32);
-    }
+    assert!(!lot.is_null());
+
     (*lot).magic = 0x107107i32 as uint32_t;
     (*lot).text1_meaning = 0i32;
 
diff --git a/src/dc_mimeparser.rs b/src/dc_mimeparser.rs
index a21bca76a..59e05a3d0 100644
--- a/src/dc_mimeparser.rs
+++ b/src/dc_mimeparser.rs
@@ -360,7 +360,7 @@ pub unsafe fn dc_mimeparser_parse(
                     b"Chat-Duration\x00" as *const u8 as *const libc::c_char,
                 );
                 if !field_0.is_null() {
-                    let duration_ms: libc::c_int = atoi((*field_0).fld_value);
+                    let duration_ms: libc::c_int = dc_atoi_null_is_0((*field_0).fld_value);
                     if duration_ms > 0i32 && duration_ms < 24i32 * 60i32 * 60i32 * 1000i32 {
                         dc_param_set_int((*part_3).param, 'd' as i32, duration_ms);
                     }
@@ -439,9 +439,7 @@ pub unsafe fn dc_mimeparser_parse(
 unsafe fn dc_mimepart_new() -> *mut dc_mimepart_t {
     let mut mimepart: *mut dc_mimepart_t;
     mimepart = calloc(1, ::std::mem::size_of::<dc_mimepart_t>()) as *mut dc_mimepart_t;
-    if mimepart.is_null() {
-        exit(33i32);
-    }
+    assert!(!mimepart.is_null());
     (*mimepart).type_0 = 0i32;
     (*mimepart).param = dc_param_new();
     mimepart
diff --git a/src/dc_msg.rs b/src/dc_msg.rs
index da0a071cf..f8f45d427 100644
--- a/src/dc_msg.rs
+++ b/src/dc_msg.rs
@@ -302,9 +302,7 @@ pub unsafe fn dc_msg_new_untyped<'a>(context: &'a Context) -> *mut dc_msg_t<'a>
 pub unsafe fn dc_msg_new<'a>(context: &'a Context, viewtype: libc::c_int) -> *mut dc_msg_t<'a> {
     let mut msg: *mut dc_msg_t;
     msg = calloc(1, ::std::mem::size_of::<dc_msg_t>()) as *mut dc_msg_t;
-    if msg.is_null() {
-        exit(15i32);
-    }
+    assert!(!msg.is_null());
     (*msg).context = context;
     (*msg).magic = 0x11561156i32 as uint32_t;
     (*msg).type_0 = viewtype;
diff --git a/src/dc_param.rs b/src/dc_param.rs
index cb6aa5a5a..7b2821397 100644
--- a/src/dc_param.rs
+++ b/src/dc_param.rs
@@ -164,7 +164,7 @@ pub unsafe fn dc_param_get_int(
     if str.is_null() {
         return def;
     }
-    let ret: int32_t = atol(str) as int32_t;
+    let ret: int32_t = to_str(str).parse().unwrap_or_default();
     free(str as *mut libc::c_void);
 
     ret
@@ -300,9 +300,7 @@ pub unsafe fn dc_param_set_int(param: *mut dc_param_t, key: libc::c_int, value:
 pub unsafe fn dc_param_new() -> *mut dc_param_t {
     let mut param: *mut dc_param_t;
     param = calloc(1, ::std::mem::size_of::<dc_param_t>()) as *mut dc_param_t;
-    if param.is_null() {
-        exit(28i32);
-    }
+    assert!(!param.is_null());
     (*param).packed = calloc(1, 1) as *mut libc::c_char;
 
     param
diff --git a/src/dc_simplify.rs b/src/dc_simplify.rs
index 9d70afe84..9ecc2329e 100644
--- a/src/dc_simplify.rs
+++ b/src/dc_simplify.rs
@@ -15,9 +15,7 @@ pub struct dc_simplify_t {
 pub unsafe fn dc_simplify_new() -> *mut dc_simplify_t {
     let simplify: *mut dc_simplify_t;
     simplify = calloc(1, ::std::mem::size_of::<dc_simplify_t>()) as *mut dc_simplify_t;
-    if simplify.is_null() {
-        exit(31i32);
-    }
+    assert!(!simplify.is_null());
 
     simplify
 }
diff --git a/src/dc_sqlite3.rs b/src/dc_sqlite3.rs
index f4df6b12c..0b1b27d9e 100644
--- a/src/dc_sqlite3.rs
+++ b/src/dc_sqlite3.rs
@@ -1166,7 +1166,7 @@ pub unsafe fn dc_sqlite3_get_config_int(
     if str.is_null() {
         return def;
     }
-    let ret = atoi(str) as int32_t;
+    let ret = dc_atoi_null_is_0(str);
     free(str as *mut libc::c_void);
     ret
 }
diff --git a/src/dc_strbuilder.rs b/src/dc_strbuilder.rs
index a5a460393..9881cd371 100644
--- a/src/dc_strbuilder.rs
+++ b/src/dc_strbuilder.rs
@@ -19,9 +19,7 @@ pub unsafe fn dc_strbuilder_init(mut strbuilder: *mut dc_strbuilder_t, init_byte
         128i32
     };
     (*strbuilder).buf = malloc((*strbuilder).allocated as usize) as *mut libc::c_char;
-    if (*strbuilder).buf.is_null() {
-        exit(38i32);
-    }
+    assert!(!(*strbuilder).buf.is_null());
     *(*strbuilder).buf.offset(0isize) = 0i32 as libc::c_char;
     (*strbuilder).free = (*strbuilder).allocated - 1i32;
     (*strbuilder).eos = (*strbuilder).buf;
@@ -47,9 +45,7 @@ pub unsafe fn dc_strbuilder_cat(
             (*strbuilder).buf as *mut libc::c_void,
             ((*strbuilder).allocated + add_bytes) as usize,
         ) as *mut libc::c_char;
-        if (*strbuilder).buf.is_null() {
-            exit(39i32);
-        }
+        assert!(!(*strbuilder).buf.is_null());
         (*strbuilder).free = (*strbuilder).free + add_bytes;
         (*strbuilder).eos = (*strbuilder).buf.offset(old_offset as isize)
     }
diff --git a/src/dc_strencode.rs b/src/dc_strencode.rs
index 66f3ffb9f..bf9b962ef 100644
--- a/src/dc_strencode.rs
+++ b/src/dc_strencode.rs
@@ -10,18 +10,9 @@ use crate::types::*;
 use crate::x::*;
 
 #[inline]
-pub fn isalnum(mut _c: libc::c_int) -> libc::c_int {
-    if _c < std::u8::MAX as libc::c_int {
-        (_c as u8 as char).is_ascii_alphanumeric() as libc::c_int
-    } else {
-        0
-    }
-}
-
-#[inline]
-pub fn isdigit(mut _c: libc::c_int) -> libc::c_int {
-    if _c < std::u8::MAX as libc::c_int {
-        (_c as u8 as char).is_ascii_digit() as libc::c_int
+pub fn isalnum(c: libc::c_int) -> libc::c_int {
+    if c < std::u8::MAX as libc::c_int {
+        (c as u8 as char).is_ascii_alphanumeric() as libc::c_int
     } else {
         0
     }
@@ -116,12 +107,16 @@ pub unsafe fn dc_urldecode(to_decode: *const libc::c_char) -> *mut libc::c_char
     buf
 }
 
-unsafe fn hex_2_int(ch: libc::c_char) -> libc::c_char {
-    return (if 0 != isdigit(ch as libc::c_int) {
-        ch as libc::c_int - '0' as i32
-    } else {
-        tolower(ch as libc::c_int) - 'a' as i32 + 10i32
-    }) as libc::c_char;
+fn hex_2_int(ch: libc::c_char) -> libc::c_char {
+    let ch = ch as u8 as char;
+    if !ch.is_ascii_hexdigit() {
+        return (ch.to_ascii_lowercase() as i32 - 'a' as i32 + 10) as libc::c_char;
+    }
+
+    match ch.to_digit(16) {
+        Some(res) => res as libc::c_char,
+        None => 0,
+    }
 }
 
 pub unsafe fn dc_encode_header_words(to_encode: *const libc::c_char) -> *mut libc::c_char {
@@ -956,4 +951,11 @@ mod tests {
             free(buf2 as *mut libc::c_void);
         }
     }
+    #[test]
+    fn test_hex_to_int() {
+        assert_eq!(hex_2_int(b'A' as libc::c_char), 10);
+        assert_eq!(hex_2_int(b'a' as libc::c_char), 10);
+        assert_eq!(hex_2_int(b'4' as libc::c_char), 4);
+        assert_eq!(hex_2_int(b'K' as libc::c_char), 20);
+    }
 }
diff --git a/src/dc_tools.rs b/src/dc_tools.rs
index 9acf9e8b7..7ed8a0f3d 100644
--- a/src/dc_tools.rs
+++ b/src/dc_tools.rs
@@ -27,14 +27,10 @@ pub unsafe fn dc_strdup(s: *const libc::c_char) -> *mut libc::c_char {
     let ret: *mut libc::c_char;
     if !s.is_null() {
         ret = strdup(s);
-        if ret.is_null() {
-            exit(16i32);
-        }
+        assert!(!ret.is_null());
     } else {
         ret = calloc(1, 1) as *mut libc::c_char;
-        if ret.is_null() {
-            exit(17i32);
-        }
+        assert!(!ret.is_null());
     }
 
     ret
@@ -50,24 +46,19 @@ pub unsafe fn dc_strdup_keep_null(s: *const libc::c_char) -> *mut libc::c_char {
 }
 
 pub unsafe fn dc_atoi_null_is_0(s: *const libc::c_char) -> libc::c_int {
-    return if !s.is_null() { atoi(s) } else { 0i32 };
+    if !s.is_null() {
+        to_str(s).parse().unwrap_or_default()
+    } else {
+        0
+    }
 }
 
-pub unsafe fn dc_atof(str: *const libc::c_char) -> libc::c_double {
-    // hack around atof() that may accept only `,` as decimal point on mac
-    let test: *mut libc::c_char = dc_mprintf(b"%f\x00" as *const u8 as *const libc::c_char, 1.2f64);
-    *test.offset(2isize) = 0i32 as libc::c_char;
-    let mut str_locale: *mut libc::c_char = dc_strdup(str);
-    dc_str_replace(
-        &mut str_locale,
-        b".\x00" as *const u8 as *const libc::c_char,
-        test.offset(1isize),
-    );
-    let f: libc::c_double = atof(str_locale);
-    free(test as *mut libc::c_void);
-    free(str_locale as *mut libc::c_void);
+pub fn dc_atof(s: *const libc::c_char) -> libc::c_double {
+    if s.is_null() {
+        return 0.;
+    }
 
-    f
+    to_str(s).parse().unwrap_or_default()
 }
 
 pub unsafe fn dc_str_replace(
@@ -184,22 +175,14 @@ pub unsafe fn dc_trim(buf: *mut libc::c_char) {
 
 /* the result must be free()'d */
 pub unsafe fn dc_strlower(in_0: *const libc::c_char) -> *mut libc::c_char {
-    let out: *mut libc::c_char = dc_strdup(in_0);
-    let mut p: *mut libc::c_char = out;
-    while 0 != *p {
-        *p = tolower(*p as libc::c_int) as libc::c_char;
-        p = p.offset(1isize)
-    }
-
-    out
+    let raw = to_cstring(to_string(in_0).to_lowercase());
+    strdup(raw.as_ptr())
 }
 
 pub unsafe fn dc_strlower_in_place(in_0: *mut libc::c_char) {
-    let mut p: *mut libc::c_char = in_0;
-    while 0 != *p {
-        *p = tolower(*p as libc::c_int) as libc::c_char;
-        p = p.offset(1isize)
-    }
+    let raw = to_cstring(to_string(in_0).to_lowercase());
+    assert_eq!(strlen(in_0), strlen(raw.as_ptr()));
+    memcpy(in_0 as *mut _, raw.as_ptr() as *const _, strlen(in_0));
 }
 
 pub unsafe fn dc_str_contains(
@@ -231,9 +214,7 @@ pub unsafe fn dc_null_terminate(
     bytes: libc::c_int,
 ) -> *mut libc::c_char {
     let out: *mut libc::c_char = malloc(bytes as usize + 1) as *mut libc::c_char;
-    if out.is_null() {
-        exit(45i32);
-    }
+    assert!(!out.is_null());
     if !in_0.is_null() && bytes > 0i32 {
         strncpy(out, in_0, bytes as usize);
     }
@@ -566,9 +547,8 @@ pub unsafe fn dc_str_to_clist(
     delimiter: *const libc::c_char,
 ) -> *mut clist {
     let list: *mut clist = clist_new();
-    if list.is_null() {
-        exit(54i32);
-    }
+    assert!(!list.is_null());
+
     if !str.is_null() && !delimiter.is_null() && strlen(delimiter) >= 1 {
         let mut p1: *const libc::c_char = str;
         loop {
@@ -779,9 +759,8 @@ unsafe fn encode_66bits_as_base64(v1: uint32_t, v2: uint32_t, fill: uint32_t) ->
     hex:    64 bit, 4 bits/character, length = 64/4 = 16 characters
     base64: 64 bit, 6 bits/character, length = 64/6 = 11 characters (plus 2 additional bits) */
     let ret: *mut libc::c_char = malloc(12) as *mut libc::c_char;
-    if ret.is_null() {
-        exit(34i32);
-    }
+    assert!(!ret.is_null());
+
     static mut chars: [libc::c_char; 65] = [
         65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87,
         88, 89, 90, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112,
@@ -1554,11 +1533,9 @@ mod tests {
 
     #[test]
     fn test_dc_atof() {
-        unsafe {
-            let f: libc::c_double = dc_atof(b"1.23\x00" as *const u8 as *const libc::c_char);
-            assert!(f > 1.22f64);
-            assert!(f < 1.24f64);
-        }
+        let f: libc::c_double = dc_atof(b"1.23\x00" as *const u8 as *const libc::c_char);
+        assert!(f > 1.22f64);
+        assert!(f < 1.24f64);
     }
 
     #[test]
diff --git a/src/types.rs b/src/types.rs
index 9619dc8ea..364e60c85 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -5,32 +5,14 @@ pub use libsqlite3_sys::*;
 pub use mmime::carray::*;
 pub use mmime::clist::*;
 
-pub type __builtin_va_list = [__va_list_tag; 1];
-#[derive(Copy, Clone)]
-#[repr(C)]
-pub struct __va_list_tag {
-    pub gp_offset: libc::c_uint,
-    pub fp_offset: libc::c_uint,
-    pub overflow_arg_area: *mut libc::c_void,
-    pub reg_save_area: *mut libc::c_void,
-}
-pub type va_list = __builtin_va_list;
-pub type __int64_t = libc::c_longlong;
-pub type __darwin_ct_rune_t = libc::c_int;
-pub type __darwin_wchar_t = libc::c_int;
-pub type __darwin_rune_t = __darwin_wchar_t;
-pub type uint64_t = libc::c_ulonglong;
-
-/**
- * Callback function that should be given to dc_context_new().
- *
- * @memberof Context
- * @param context The context object as returned by dc_context_new().
- * @param event one of the @ref DC_EVENT constants
- * @param data1 depends on the event parameter
- * @param data2 depends on the event parameter
- * @return return 0 unless stated otherwise in the event parameter documentation
- */
+/// Callback function that should be given to dc_context_new().
+///
+/// @memberof Context
+/// @param context The context object as returned by dc_context_new().
+/// @param event one of the @ref DC_EVENT constants
+/// @param data1 depends on the event parameter
+/// @param data2 depends on the event parameter
+/// @return return 0 unless stated otherwise in the event parameter documentation
 pub type dc_callback_t =
     unsafe extern "C" fn(_: &Context, _: Event, _: uintptr_t, _: uintptr_t) -> uintptr_t;
 
@@ -62,15 +44,9 @@ pub type sqlite3_int64 = sqlite_int64;
 pub type int32_t = libc::int32_t;
 pub type int64_t = libc::int64_t;
 pub type uintptr_t = libc::uintptr_t;
-pub type __uint8_t = libc::uint8_t;
-pub type __uint16_t = libc::uint16_t;
-pub type __int32_t = libc::int32_t;
-pub type __uint64_t = libc::uint64_t;
-
 pub type size_t = libc::size_t;
 pub type ssize_t = libc::ssize_t;
 pub type uint32_t = libc::c_uint;
 pub type uint8_t = libc::c_uchar;
 pub type uint16_t = libc::c_ushort;
-
-pub type __uint32_t = libc::c_uint;
+pub type uint64_t = libc::uint64_t;
diff --git a/src/x.rs b/src/x.rs
index 4c3a5f816..bacb5d900 100644
--- a/src/x.rs
+++ b/src/x.rs
@@ -3,9 +3,8 @@ use crate::dc_tools::*;
 use crate::types::*;
 
 pub use libc::{
-    atoi, calloc, exit, free, malloc, memcmp, memcpy, memmove, memset, realloc, strcat, strchr,
-    strcmp, strcpy, strcspn, strlen, strncmp, strncpy, strrchr, strspn, strstr, strtol, system,
-    tolower, write,
+    calloc, exit, free, malloc, memcmp, memcpy, memmove, memset, realloc, strcat, strchr, strcmp,
+    strcpy, strcspn, strlen, strncmp, strncpy, strrchr, strspn, strstr, strtol, system,
 };
 
 pub unsafe fn strdup(s: *const libc::c_char) -> *mut libc::c_char {
@@ -43,7 +42,6 @@ extern "C" {
             unsafe extern "C" fn(_: *const libc::c_void, _: *const libc::c_void) -> libc::c_int,
         >,
     );
-    pub fn atol(_: *const libc::c_char) -> libc::c_long;
     pub fn vsnprintf(
         _: *mut libc::c_char,
         _: libc::c_ulong,
@@ -57,14 +55,6 @@ extern "C" {
     pub fn dc_mprintf(format: *const libc::c_char, _: ...) -> *mut libc::c_char;
 }
 
-#[cfg(not(target_os = "android"))]
-pub use libc::atof;
-
-#[cfg(target_os = "android")]
-pub unsafe fn atof(nptr: *mut libc::c_char) -> libc::c_double {
-    libc::strtod(nptr, std::ptr::null_mut())
-}
-
 pub(crate) unsafe fn strcasecmp(s1: *const libc::c_char, s2: *const libc::c_char) -> libc::c_int {
     let s1 = std::ffi::CStr::from_ptr(s1)
         .to_string_lossy()
@@ -105,14 +95,6 @@ mod tests {
     use super::*;
     use crate::dc_tools::to_string;
 
-    #[test]
-    fn test_atox() {
-        unsafe {
-            assert_eq!(atol(b"\x00" as *const u8 as *const libc::c_char), 0);
-            assert_eq!(atoi(b"\x00" as *const u8 as *const libc::c_char), 0);
-        }
-    }
-
     #[test]
     fn test_strndup() {
         unsafe {