opencv在交叉编译的时候的一些常见报错和处理---How to use std::stoul and std::stoull in Android?
How to use std::stoul and std::stoull in Android?
Ask Question Asked 8 years, 7 months ago Modified 6 years, 2 months ago Viewed 13k timesC++11 has two new string conversion functions into unsigned long
and long long
: std::stoul()
and std::stoll()
.
The recent Android NDK r9 introduces Clang 3.3 compiler which is said to be C++11 feature complete. There are prototypes for these functions deep inside NDK, however I cannot use them.
What do I need to do to use them?
P.S. I already do LOCAL_CPPFLAGS += -std=c++11
Note: __GXX_EXPERIMENTAL_CXX0X__
is defined by adding -std=gnu++11
to APP_CXXFLAGS
or LOCAL_CXXFLAGS
Detailed Test log: Built using NDK version r8e
jni/Application.mk:
APP_STL := gnustl_static
APP_CXXFLAGS += -std=gnu++11
NDK_TOOLCHAIN_VERSION := 4.7
jni/Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := cxx11
LOCAL_SRC_FILES := cxx11.cpp
include $(BUILD_EXECUTABLE)
jni/cxx11.cpp:
#include
#include
int main(int argc, char* argv[]) {
#if defined(__GXX_EXPERIMENTAL_CXX0X__)
std::cout<<"__GXX_EXPERIMENTAL_CXX0X__ defined."<
Output on Nexus 4 (Android 4.3):
u0_a51@mako:/ $ /data/local/tmp/cxx11
__GXX_EXPERIMENTAL_CXX0X__ defined.
_GLIBCXX_USE_C99 not defined.
_GLIBCXX_HAVE_BROKEN_VSWPRINTF not defined.
No support for stoll/stoul.
Share
edited Aug 8, 2013 at 12:59
answered Aug 8, 2013 at 11:16

- Any chance to replace stdlib? – Sergey K. Aug 8, 2013 at 11:19
- @SergeyK. Try CrystaX's Android NDK, which seems to have some fixes over the Vanilla Android NDK. I am looking to explore it as well. – Samveen Aug 8, 2013 at 11:43
- Have you tried NDK r9? Maybe we can define _GLIBCXX_USE_C99 manually? – Sergey K. Aug 8, 2013 at 11:44
-
@SergeyK. Naah. Already tried
LOCAL_CFLAGS := -D _GLIBCXX_USE_C99=1
. It's a very deep-rooted problem. – Samveen Aug 8, 2013 at 11:46 - Ok, this seems to be a great answer. – Sergey K. Aug 8, 2013 at 12:17
-
Did this also fix the issue of access to the
unsigned long
andlong long
variants of the functions(stoul
andstoll
)? – Samveen Feb 22, 2016 at 5:14 - That solution helped me with stoul(). Thanks. – Stranger May 5, 2017 at 16:18
-stdlib=libc++ -std=c++11
for the LOCAL_CFLAGS) – FDinoff Jul 30, 2013 at 15:24-std=c++11
– Sergey K. Jul 30, 2013 at 16:01-stdlib=libc++
is also needed make sure you try it – aaronman Jul 30, 2013 at 17:14-E
to show the preprocessor output you can see thatbits/basic_string.h
is included and that appears to be wherestoll
is defined howeverstoll
does not appear in the preprocessor output. – FDinoff Jul 30, 2013 at 18:50