update boost version requirement to 1.71

Builds/CMake/deps/Boost.cmake

@@ -44,7 +44,7 @@ else()
 endif()
 # TBD:
 # Boost_USE_DEBUG_RUNTIME:  When ON, uses Boost libraries linked against the
-find_package(Boost 1.70 REQUIRED
+find_package(Boost 1.71 REQUIRED
   COMPONENTS
     chrono
     container

Builds/VisualStudio2017/README.md

@@ -17,11 +17,13 @@ need these software components
 | [Visual Studio 2017](README.md#install-visual-studio-2017)| 15.5.4 |
 | [Git for Windows](README.md#install-git-for-windows)| 2.16.1 |
 | [OpenSSL Library](README.md#install-openssl) | 1.1.1L |
-| [Boost library](README.md#build-boost) | 1.70.0 |
+| [Boost library](README.md#build-boost) | 1.71.0** |
 | [CMake for Windows](README.md#optional-install-cmake-for-windows)* | 3.12 |
 
 \* Only needed if not using the integrated CMake in VS 2017 and prefer generating dedicated project/solution files.
 
+\*\* Boost 1.71 to 1.77 is required. Version 1.78 and later won't work.
+
 ## Install Software
 
 ### Install Visual Studio 2017
@@ -80,13 +82,13 @@ to get the correct 32-/64-bit variant.
 
 ### Build Boost
 
-Boost 1.70 or later is required.
+Boost 1.71 to 1.77 is required.
 
 After [downloading boost](http://www.boost.org/users/download/) and unpacking it
-to `c:\lib`. As of this writing, the most recent version of boost is 1.70.0,
-which will unpack into a directory named `boost_1_70_0`. We recommended either
+to `c:\lib`. As of this writing, the recommended version of boost is 1.71.0,
+which will unpack into a directory named `boost_1_71_0`. We recommended either
 renaming this directory to `boost`, or creating a junction link `mklink /J boost
-boost_1_70_0`, so that you can more easily switch between versions.
+boost_1_71_0`, so that you can more easily switch between versions.
 
 Next, open **Developer Command Prompt** and type the following commands
 
@@ -216,7 +218,7 @@ execute the following commands within your `rippled` cloned repository:
 ```
 mkdir build\cmake
 cd build\cmake
-cmake ..\.. -G"Visual Studio 15 2017 Win64" -DBOOST_ROOT="C:\lib\boost_1_70_0" -DOPENSSL_ROOT="C:\lib\OpenSSL-Win64" -DCMAKE_GENERATOR_TOOLSET=host=x64
+cmake ..\.. -G"Visual Studio 15 2017 Win64" -DBOOST_ROOT="C:\lib\boost_1_71_0" -DOPENSSL_ROOT="C:\lib\OpenSSL-Win64" -DCMAKE_GENERATOR_TOOLSET=host=x64
 ```
 Now launch Visual Studio 2017 and select **File | Open | Project/Solution**.
 Navigate to the `build\cmake` folder created above and select the `rippled.sln`

Builds/linux/README.md

@@ -33,13 +33,13 @@ protobuf will give errors.
 
 ### Build Boost
 
-Boost 1.70 or later is required. We recommend downloading and compiling boost
+Boost 1.71 to 1.77 is required. Version 1.78 and later won't work. We recommend downloading and compiling boost
 with the following process: After changing to the directory where
 you wish to download and compile boost, run
 ``` 
-$ wget https://boostorg.jfrog.io/artifactory/main/release/1.70.0/source/boost_1_70_0.tar.gz
-$ tar -xzf boost_1_70_0.tar.gz
-$ cd boost_1_70_0
+$ wget https://boostorg.jfrog.io/artifactory/main/release/1.71.0/source/boost_1_71_0.tar.gz
+$ tar -xzf boost_1_71_0.tar.gz
+$ cd boost_1_71_0
 $ ./bootstrap.sh
 $ ./b2 headers
 $ ./b2 -j<Num Parallel>
@@ -88,14 +88,14 @@ git checkout develop
 If you didn't persistently set the `BOOST_ROOT` environment variable to the
 directory in which you compiled boost, then you should set it temporarily.
 
-For example, you built Boost in your home directory `~/boost_1_70_0`, you
+For example, you built Boost in your home directory `~/boost_1_71_0`, you
 would do for any shell in which you want to build:
 
 ```
-export BOOST_ROOT=~/boost_1_70_0
+export BOOST_ROOT=~/boost_1_71_0
 ```
 
-Alternatively, you can add `DBOOST_ROOT=~/boost_1_70_0` to the command line when
+Alternatively, you can add `-DBOOST_ROOT=~/boost_1_71_0` to the command line when
 invoking `cmake`.
 
 ### Generate Configuration